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Daybetter 800 Lumens 120V 9W RGB+2700-6500K bulbs (BK7231N/CB2L/BP5758D)

dwildstr 4728 27
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  • These bulbs are dirt cheap Tuya bulbs (I get them in a 12-pack off of Amazon for between $4 and $5 per bulb, a very reasonable price for bright RGBCW bulbs), and I discovered to my delight that they're OTA flashable using the tuya-cloudcutter exploit. I'll start with notes about the various configurations I used for tuya-cloudcutter and OpenBeken, and then move on to the hardware teardown.

    In tuya-cloudcutter, the device profile "Tuya-Generic/E27-RGBCW-Smart-Life-WB2L_M1" works fantastically. The chipset is BK7231N; flash an OpenBeken firmware designed for that chipset. In OpenBeken, the necessary module setup is to make P7 BP5758D_CLK, and P8 BP5758D_DAT. Additionally the channels needed remapping, so I added in the startup command "BP5758D_Map 2 1 0 4 5". This information is enough to get these bulbs nicely out of the Tuya dungeon and working great on open-source local-control firmware without having to do any hardware surgery.

    Over on an OpenBeken issue I opened, they recommended I post a teardown of this hitherto unknown device, and I had one bricked bulb (onto which I had carelessly flashed a BK7231T firmware) and another I had taken the dome off of and expected to sacrifice. First, some pictures of completely unaltered bulbs:
    Daybetter 800 Lumens 120V 9W RGB+2700-6500K bulbs (BK7231N/CB2L/BP5758D)Daybetter 800 Lumens 120V 9W RGB+2700-6500K bulbs (BK7231N/CB2L/BP5758D)
    They don't really have any model name or number beyond the extensive descriptive text on the bulbs. The translucent dome is glued on and comes off with a bit of heavy-duty twisting and squeezing. Once removed, the light PCB and the tip of the MCU PCB are visible, as is usually the case:
    Daybetter 800 Lumens 120V 9W RGB+2700-6500K bulbs (BK7231N/CB2L/BP5758D)
    This board has 15 warm-white LEDs, 10 cool-white LEDs, and 3 LEDs in each of red, blue, and green. The most significant other components are that IC which is identified by the silkscreen as a BP5758, and a four-pin connector which transmits data and power from the MCU PCB (note that this differs from a lot of bulb teardowns --- 6-pin connectors are much more common!). Based on closer inspection later, I believe the pin closest to the BP5758 (the one on the upper left in the picture above) carries the BP5758 clock signal, the one close to both the BP5758 and the surface-mount resistor (upper right) carries 120V DC power, the one closest to the MCU cutout (lower left) is BP5758 data, and the one close to the cluster of resistors (lower right) is ground. At one point I was trying to determine which pins carried voltage and how much and accidentally shorted out the 120V and ground pins. This killed the bulb and the physical damage is visible in a later photo.

    This board's schematic seems to be extremely close to one found in a Chinese-language report from a expo showing off Tuya bulbs which served as Bluetooth beacons.
    Daybetter 800 Lumens 120V 9W RGB+2700-6500K bulbs (BK7231N/CB2L/BP5758D)

    Disassembling the bulb further required taking off a lot of glue. The light PCB was glued down around the edges, and there was also an enormous glob of glue holding the MCU onto the LED PCB (seen in the photo above. The large glue-glob was easy to cut, and the glue around the edges succumbed to light but consistent upwards prying around the edges of the light board. Removal of this PCB allowed a glimpse of the interior:
    Daybetter 800 Lumens 120V 9W RGB+2700-6500K bulbs (BK7231N/CB2L/BP5758D)
    This board gets a better picture after the physical destruction of the bulb base. It was, as expected, connected to the Edison screw for power by two wires, one of which was an unsoldered contact with the screw wall; the other was soldered onto the button at the bottom. The plastic around the base of the screw was cut until it was possible to take the screw base and the PCB out, whereupon the full PCB, along with its connections to the Edison base, could be photographed.
    Daybetter 800 Lumens 120V 9W RGB+2700-6500K bulbs (BK7231N/CB2L/BP5758D) Daybetter 800 Lumens 120V 9W RGB+2700-6500K bulbs (BK7231N/CB2L/BP5758D)
    Most of what is on here appears to be power-supply stuff. The 4-pin IC on the narrow end is a rectifier with, as far as I can tell, no silkscreen. The 4-pin IC in the wider section is labeled as a KP35026, which seems to be a 3.3V power-supply. The scorch mark directly below the left side of the ICU shows where my careless short seems to have caused a SMD resistor to explode.

    The MCU itself is labeled as a CB2L, which is a pretty standard Tuya Wifi unit built around a BK7231N chipset. As far as I can tell, pins P6, P26, and P24 are not used at all; P7 and P8 have traces to the LED-board connection.

    AFAICT, this is mostly a pretty ordinary 5-channel bulb using a BP5758 for current control. It has the exact same configuration as a Nous P3, and as far as I can tell most of the same hardware although the physical layout on the PCB is a bit different.

    Cool? Ranking DIY
    About Author
    dwildstr
    Level 4  
    Offline 
    dwildstr wrote 7 posts with rating 4. Been with us since 2022 year.
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  • #2 20229249
    p.kaczmarek2
    Moderator Smart Home
    Thanks for the teardown. I see you also noticed it's similarity to Nous P3. I wonder if that Tuya-cloudcutter profile would work for P3 as well. I didn't test that, as my default routine is always to use wires and provide next flash dump for cloudcutting analysis.

    BP5758 is a nice little chip. Those 4 gold pins routed out of the main board to LEDs board looks strange, without BP5758 (or similar driver) it would not be possible to control 5 sets of simple LEDs with 4 pins.

    I've attached BP5758 datasheet.

    EDIT:
    Quote:

    I had one bricked bulb (onto which I had carelessly flashed a BK7231T firmware)

    have you managed to recover that?
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  • #3 20229994
    dwildstr
    Level 4  
    Quote:
    Quote:
    I had one bricked bulb (onto which I had carelessly flashed a BK7231T firmware)

    have you managed to recover that?


    Nope. I figure it's probably doable by desoldering the BK7231N chip, hooking it up to a USB-UART adapter, and flashing firmware the good old bare-metal way, but I'm not really much of a hardware person and these things only cost $4 so I'm prepared to write it off rather than try to bring it back to life. The not-being-a-hardware-person is also why I didn't try to recover the stock firmware from an unmodified bulb --- since a generic profile works with cloudcutter, it didn't seem very urgent to get a new profile for this bulb.
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  • #4 20238464
    leonbotha69
    Level 4  
    Hi dwildstr

    I have a similar bulb - "BNETA" brand - that has the same layout and also use the CB2L chipset.
    I have not been able to successfully get tuya-cloudcutter to work.

    I only have a RPI 3B to run linux on.
    I followed the instructions as per - HOST_SPECIFIC_INSTRUCTIONS.md, but i am not getting anywhere.
    Any pointers will be welcome.

    Z
  • #5 20238569
    p.kaczmarek2
    Moderator Smart Home
    @leonbotha69 I used Tuya-cloudcutter once and it worked well. Can you be more specific where is your issue?

    For the record, I used it with Ubuntu virtual machine ran on windows and external wiFi USB dongle (that is capable of creating AP).
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  • #6 20239027
    leonbotha69
    Level 4  
    Hi p.kaczmarek2
    I place the bulb in "AP" mode - fast flashing, but tuya-cloudcutter never see the bulb.
    My android phone with the Tuya Smart app detects the bulb every time.
    I tried to set the bulb via Bluetooth to accept the cloudcutterflash AP, but i get a message that the wifi AP could not be found

    I have tried:
    1. RPI as per the instructions
    2. Win 10 with virtual ubuntu did not see my desktop wifi adaptor, so that was a bust.
    3. Ubuntu on a laptop as per instructions

    Bulb is not detected
  • #7 20241675
    leonbotha69
    Level 4  
    Hi p.kaczmarek2

    Just some update.

    I made some progress - reimaged my RPI and it can now see the cloudcutter AP and cloudcutter is detecting my bulb - "SmartLife-7EC4"
    I have not managed to "cut" it as i am getting: SSL Error on 12 ('10.42.42.24', 62644): [SSL: DECRYPTION_FAILED_OR_BAD_RECORD_MAC] decryption failed or bad record mac (_ssl.c:1129)

    I presume that it is then not 100% the same profile as the one in this tread.
    Let me see on the weekend if i can sacrifice one to do a code dump.

    Below is some more info from cloudcutter -

    Scanning for "A-" "Geeni-" "GRID-" "iHome-" "LDV SMART+-" "Merkury-" "Nexxt Home-" "SL-CreeLighting-" "SL-FLSNT-" "SmartLife-" "TreatLife-SL-" SSID...
    Scanning for "A-" "Geeni-" "GRID-" "iHome-" "LDV SMART+-" "Merkury-" "Nexxt Home-" "SL-CreeLighting-" "SL-FLSNT-" "SmartLife-" "TreatLife-SL-" SSID...
    Found access point name: "SmartLife-7EC4", trying to connect..
    Device 'wlan0' successfully activated with '0acdc3d3-55cc-4935-9c31-dcaa4eeda72a'.
    Connected to access point.
    Configured device to connect to 'cloudcutterflash'
    Device is connecting to 'cloudcutterflash' access point. Passphrase for the AP is 'abcdabcd' (without ')
    Cutting device off from cloud..
    ==> Wait for 20-30 seconds for the device to connect to 'cloudcutterflash'. This script will then show the activation requests sent by the device, and tell you whether local activation was successful.
    Using WLAN adapter: wlan0
    Oct 18 14:09:38 dnsmasq[15]: started, version 2.80 cachesize 150
    Oct 18 14:09:38 dnsmasq[15]: compile time options: IPv6 GNU-getopt DBus i18n IDN DHCP DHCPv6 no-Lua TFTP conntrack ipset auth DNSSEC loop-detect inotify dumpfile
    Oct 18 14:09:38 dnsmasq-dhcp[15]: DHCP, IP range 10.42.42.10 -- 10.42.42.40, lease time 12h
    Oct 18 14:09:38 dnsmasq-dhcp[15]: DHCP, sockets bound exclusively to interface wlan0
    Oct 18 14:09:38 dnsmasq[15]: read /etc/hosts - 5 addresses
    Configuration file: /dev/stdin
    wlan0: Could not connect to kernel driver
    Using interface wlan0 with hwaddr b8:27:eb:1d:65:34 and ssid "cloudcutterflash"
    wlan0: interface state UNINITIALIZED->ENABLED
    wlan0: AP-ENABLED
    Oct 18 14:09:44 dnsmasq-dhcp[15]: 842012285 available DHCP range: 10.42.42.10 -- 10.42.42.40
    Oct 18 14:09:44 dnsmasq-dhcp[15]: 842012285 client provides name: wlan0
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 DHCPDISCOVER(wlan0) a0:92:08:3e:7e:c4
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 tags: wlan0
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 DHCPOFFER(wlan0) 10.42.42.24 a0:92:08:3e:7e:c4
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 requested options: 1:netmask, 3:router, 28:broadcast, 6:dns-server
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 next server: 10.42.42.1
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 sent size: 1 option: 53 message-type 2
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 sent size: 4 option: 54 server-identifier 10.42.42.1
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 sent size: 4 option: 51 lease-time 12h
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 sent size: 4 option: 58 T1 6h
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 sent size: 4 option: 59 T2 10h30m
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 sent size: 4 option: 1 netmask 255.255.255.0
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 sent size: 4 option: 28 broadcast 10.42.42.255
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 sent size: 4 option: 3 router 10.42.42.1
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 sent size: 4 option: 6 dns-server 10.42.42.1
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 available DHCP range: 10.42.42.10 -- 10.42.42.40
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 client provides name: wlan0
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 DHCPDISCOVER(wlan0) a0:92:08:3e:7e:c4
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 tags: wlan0
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 DHCPOFFER(wlan0) 10.42.42.24 a0:92:08:3e:7e:c4
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 requested options: 1:netmask, 3:router, 28:broadcast, 6:dns-server
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 next server: 10.42.42.1
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 sent size: 1 option: 53 message-type 2
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 sent size: 4 option: 54 server-identifier 10.42.42.1
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 sent size: 4 option: 51 lease-time 12h
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 sent size: 4 option: 58 T1 6h
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 sent size: 4 option: 59 T2 10h30m
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 sent size: 4 option: 1 netmask 255.255.255.0
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 sent size: 4 option: 28 broadcast 10.42.42.255
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 sent size: 4 option: 3 router 10.42.42.1
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 sent size: 4 option: 6 dns-server 10.42.42.1
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 available DHCP range: 10.42.42.10 -- 10.42.42.40
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 client provides name: wlan0
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 DHCPREQUEST(wlan0) 10.42.42.24 a0:92:08:3e:7e:c4
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 tags: wlan0
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 DHCPACK(wlan0) 10.42.42.24 a0:92:08:3e:7e:c4 wlan0
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 requested options: 1:netmask, 3:router, 28:broadcast, 6:dns-server
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 next server: 10.42.42.1
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 sent size: 1 option: 53 message-type 5
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 sent size: 4 option: 54 server-identifier 10.42.42.1
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 sent size: 4 option: 51 lease-time 12h
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 sent size: 4 option: 58 T1 6h
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 sent size: 4 option: 59 T2 10h30m
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 sent size: 4 option: 1 netmask 255.255.255.0
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 sent size: 4 option: 28 broadcast 10.42.42.255
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 sent size: 4 option: 3 router 10.42.42.1
    Oct 18 14:09:47 dnsmasq-dhcp[15]: 842012285 sent size: 4 option: 6 dns-server 10.42.42.1
    Oct 18 14:10:05 dnsmasq[15]: query[A] h3.iot-dns.com from 10.42.42.24
    Oct 18 14:10:05 dnsmasq[15]: config h3.iot-dns.com is 10.42.42.1
    Using PSK v1 - Received PSK ID version 02
    [W 221018 14:10:05 iostream:1406] SSL Error on 12 ('10.42.42.24', 62644): [SSL: DECRYPTION_FAILED_OR_BAD_RECORD_MAC] decryption failed or bad record mac (_ssl.c:1129)
    Using PSK v1 - Received PSK ID version 02
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  • #8 20241727
    p.kaczmarek2
    Moderator Smart Home
    Please pair your device with a preferrably dummy SSID before doing full 2MB flash dump. Remember that SSID data is stored in this dump, so people would be able to find out your WiFi pass. Doing paired dump is better because then it consists XML schema of the device that is, as far as I know, downloaded at the time of pairing.
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  • #9 20241778
    leonbotha69
    Level 4  
    Hi p.kaczmarek2

    Yes, i shall use an old Linksys router i have that is not in use to do the dump.

    Regards
    Z
  • #10 20242426
    p.kaczmarek2
    Moderator Smart Home
    Very well. Safety always goes first. I am looking forward to see your full 2MB flash memory data.
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  • #11 20333851
    dwildstr
    Level 4  
    Big update: a few (4 out of 24!) of my Daybetter bulbs turn out to have significantly different hardware. Below is a picture of two different bulbs from my stash; they came out of the same box of 12, and look the same externally.

    Daybetter 800 Lumens 120V 9W RGB+2700-6500K bulbs (BK7231N/CB2L/BP5758D)

    They look the same internally too, and as far as I can tell use the exact same two underlying PCBs, but they differ in two significant ways: the one on the right is just like the bulbs I described before, with a BP5758D driver on the LED board, and a CB2L Tuya module with a BK7231N MCU. The one on the left has those two components swapped out for two different ones that are pin-equivalent: an SM2135 on the LED board, and a WB2L Tuya module with a BK7231T MCU. These are not interchangeable for flashing purposes; they use different firmwares, and the driver chips require different configurations, so it's actually pretty important to know which you have.

    If you want to check undestructively which you have, it looks like a near-certainty that the CB2Ls are stuck on 1.2.16 firmware while the WB2Ls are on 2.9.6. This might not be the case for fresh bulbs that have never been on Wifi and haven't automatically updated.

    If you're content with a mildly invasive procedure to check, popping off the dome and checking which driver chip is on the LED board and what text is on the MCU will do. Some of the CB2Ls aren't labeled as such in a visible place, but most are. Also, I haven't seen any bulbs with the CM2L/SM2135 or WB2L/BP5758D combination, but there might be, especially as the interface between the LED boards and the power supply/MCU board is unchanged between the models and would be interoperable on the hardware level.

    Anyways, the significant differences for flashing purposes are: first, match firmware to the BK7231 variant present (and guessing wrong will brick your bulb, so best not to guess), and second, any new firmware probably needs a configuration for the light drivers (guessing this wrong will simply make your bulb not work until reconfigured and restarted). The pins are still P7 for the clock and P8 for data, but the right driver needs to be selected, either BP5758D or SM2135.
    [/i]
  • #12 20333932
    p.kaczmarek2
    Moderator Smart Home
    From my experience, removing the dome from bulb is easy in case of Tuya bulbs and is not destructive. Checking if it's WB2L or CB2L should be quick. Still, good to know. Luckily both BP5758D and SM2135 are supported
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  • #13 20336414
    dwildstr
    Level 4  
    I've now flashed 36 bulbs and the final tally is: 4 WB2L/SM2135s to 32 CB2L/BP5758Ds It really looks like the WB2L/SM2135 configuration might have been some sort of supply chain hiccup in the manufacturing end, or it's possible I was buying these at exactly the time some change-over was happening, but certainly within my experience, the WB2L/SM2135 bulbs seem to be an aberration. Work just as well as the others, though.
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  • #14 20336453
    p.kaczmarek2
    Moderator Smart Home
    We just recently had a BK7231T-based CB2S module (yes, with T!) in other thread so nothing will surprise me now.
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  • #15 20396354
    wascott
    Level 2  
    I ordered the Daybetter A5W 800 lumens 120V 9W rgb+2700-8500K bulbs.
    I've managed to use Cloudcutter to download OpenBK latest code (Build: Build on Jan 20 2023 16:50:42 version 1.15.346)

    I've not had any success getting the bulb to turn on.
    I did see someone comment that the bulb was WB2L/SM2135 so I've tried multiple pin configs for
    24 -SM2235DAT 0
    26 -SM2235CLK 0

    No joy.
    Can someone please show the proper pin and startup configs?
    Thanks.

    Took a look under the top and verified its a WB2L (the flash probably would not have worked otherwise).
    I was barely able to make out BP5758 on the chip by the LEDs.
    I've set the pins to below and cycled power.
    24 BP5758D_DAT
    26 BP5758D_CLK

    The web gui does not show led bars even after setting Flag 4.

    Still no light.
  • #16 20396474
    p.kaczmarek2
    Moderator Smart Home
    It looks like you've confused SM2235 (10 bit version) with SM2135 (8 bit version).
    Please select proper pins for SM2135:
    Daybetter 800 Lumens 120V 9W RGB+2700-6500K bulbs (BK7231N/CB2L/BP5758D)
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  • #17 20396731
    wascott
    Level 2  
    I found a post from leonbotha69

    The cfg_pins for this bulb is:
    P7 (PWM1) - BP5758D_DAT
    P8 (PWM2) - BP5758D_CLK

    I finally have light!
    Early stages but colors appear correct.
    Still testing white and cool white.
    Btw, BP5758D_Map 2 1 0 4 5 for the startup script.

    I'm controlling it from Home Assistant.
  • #18 20396736
    p.kaczmarek2
    Moderator Smart Home
    @wascott I can add a template to the database, but can you post here at least a photo of the bulb or of the packaging?
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  • #19 20396754
    wascott
    Level 2  
    Updated map for white/cool white
    BP5758D_Map 2 1 0 3 4

    Here are the pictures, don't know what you wanted.
    Also, maybe a note about at least 2 different models, one with the BK7231T and one with the N.
    Mine was the T version. Daybetter 800 Lumens 120V 9W RGB+2700-6500K bulbs (BK7231N/CB2L/BP5758D) Daybetter 800 Lumens 120V 9W RGB+2700-6500K bulbs (BK7231N/CB2L/BP5758D) Daybetter 800 Lumens 120V 9W RGB+2700-6500K bulbs (BK7231N/CB2L/BP5758D) Daybetter 800 Lumens 120V 9W RGB+2700-6500K bulbs (BK7231N/CB2L/BP5758D) Daybetter 800 Lumens 120V 9W RGB+2700-6500K bulbs (BK7231N/CB2L/BP5758D)
  • #20 20465764
    Zain00
    Level 10  
    I received a pack of Daybetter bulbs. they use WB2L & firmware V2.9.25 that can be flashed with cloudcutter.
    P7 (PWM1) - BP5758D_DAT
    P8 (PWM2) - BP5758D_CLK

    Daybetter 800 Lumens 120V 9W RGB+2700-6500K bulbs (BK7231N/CB2L/BP5758D)

    WARNING: When I first try these bulbs, they gave me a mild electric shock! I haven’t even start to disassemble them. It seems there's something faulty with the circuit they use (I experienced electric shock from 2 different bulbs after unscrewing them from the lamp).
  • #21 20465778
    p.kaczmarek2
    Moderator Smart Home
    Please be careful. Electrolytic capacitors can keep they charge long after the circuit is disconnected from mains. Especially if there is no bleeder resistor.

    Regarding the photo, the capacitors are looking strange - do they have any marking?

    I also see that WB2L might have covered programming pads. That's good that we have OTA hack. Otherwise you'd have to use this method:
    https://www.youtube.com/watch?v=2e1SUQNMrgY&ab_channel=Elektrodacom
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  • #22 20466254
    Zain00
    Level 10  
    Daybetter 800 Lumens 120V 9W RGB+2700-6500K bulbs (BK7231N/CB2L/BP5758D) Daybetter 800 Lumens 120V 9W RGB+2700-6500K bulbs (BK7231N/CB2L/BP5758D) Daybetter 800 Lumens 120V 9W RGB+2700-6500K bulbs (BK7231N/CB2L/BP5758D) Daybetter 800 Lumens 120V 9W RGB+2700-6500K bulbs (BK7231N/CB2L/BP5758D)

    I'm usually careful not to touch the capacitors when I open any device, but this time I was shocked by just touching the E27 base.
    Here are some pictures of the board. In this bulb I put ESP32 to try Tasmota. I have to say Openbeken handles LED drivers far better than Tasmota.
  • #23 20466258
    p.kaczmarek2
    Moderator Smart Home
    Those capacitors are indeed strangely soldered. They used THT components as SMD ones.
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  • #24 20493359
    ryny24
    Level 1  
    This thread REALLY helped me. My bulbs were giving me the wrong colors after flashing OpenBeken. Thankfully, the "BP5758D_Map 2 1 0 3 4" works great.
    The only thing I notice is the bulb is slightly dimmer than original firmware. Not very noticeable at 100%, but very noticeable the lower you go. I'll keep playing around.

    Thank you!
  • #25 20493408
    p.kaczmarek2
    Moderator Smart Home
    Please remember that you can also change the current of the LEDs. Search for "BP5758D" in our commands documentation:
    https://github.com/openshwprojects/OpenBK7231T_App/blob/main/docs/commands.md
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  • #26 20940473
    wolvenmoon
    Level 2  
    I'm noticing an issue w/ color accuracy on blue-red blends. I flashed over to ESPhome firmware via home assistant. Blue appears to be dominating where if I pick a purple that's, say, RGB 110/0/255 on a cloudcut bulb on ESPhome and a cloud attached bulb, the cloud attached bulb is overwhelmingly more blue to the point I don't have color parity with Stock firmware 110/0/255 until I go to ESPhome 110/0/175. However, when I go to a teal like 0/255/255, both bulbs appear to be the same.


    I'm not sure quite what to do here since this is my first time cloud cutting. It appears that ESPhome is configured to drive 30/30/30/55/55mA for red, green, blue, cold, and warm respectively. Should I be looking at increasing current through the red LEDs or what?

    I figured I'd ask folks who were older and wiser before I did much more.
  • #27 20940602
    p.kaczmarek2
    Moderator Smart Home
    It's a known problem. We've developed a solution for that in OpenBeken, it's caled color/gamma calibration: https://github.com/openshwprojects/OpenBK7231T_App/blob/main/docs/led_gamma_control.md
    You can use cal subcommand to set RGB calibration values from color-picker or parameters.

    I wouldn't expect that current calibration is bad. As far as I know, even Tuya is using the same current for all 3 RGB channels.
    Helpful post? Buy me a coffee.
  • #28 20942069
    wolvenmoon
    Level 2  
    Alrighty!

    I went ahead and manually calibrated the bulb to Home Assistant using 255,255,255 and 0,255,255, 255,0,255, and 255,255,0 as reference colors loosely matched to my Wacom Cintiq in its factory-calibrated mode (it's not been calibrated for 8 years). This was done by eye, not with a meter, so it is imperfect but I've decided it's 'good enough' for me. https://esphome.io/components/light/rgb.html gives a hint re: setting max power percentages based on gamma that I've used, here.

    output:
      - platform: bp5758d
        id: output_red
        channel: 3
        current: 30
        #max_power: 100%    
      - platform: bp5758d
        id: output_green
        channel: 2
        current: 30 #Originally 30
        #max_power: 67% without gamma included (default 2.8, so .67^2.8)
        max_power: 32.6%
      - platform: bp5758d
        id: output_blue
        channel: 1
        current: 30 #Originally 30
        #max_power: 50% without gamma included
        max_power: 14.4%
      - platform: bp5758d
        id: output_cold
        channel: 5
        current: 55
      - platform: bp5758d
        id: output_warm
        channel: 4
        current: 55
    


    I hope this helps someone! :)

Topic summary

The discussion revolves around the Daybetter 800 Lumens 120V 9W RGB+2700-6500K bulbs, which utilize the BK7231N chipset and can be flashed with OpenBeken firmware using the tuya-cloudcutter exploit. Users share their experiences with different configurations for flashing, including the necessary pin mappings for the BP5758D driver. Some users report issues with detection and flashing, while others successfully flash their bulbs and adjust settings for color accuracy. Notably, variations in hardware were discovered among bulbs from the same batch, leading to different firmware requirements. Safety concerns regarding electric shocks from the bulbs are also raised, emphasizing the importance of caution when handling electronic components.
Summary generated by the language model.
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