>>21110395 I am referring to the default version of the device having data captured for a few days. I have seen a few videos of unboxing and showing the functionality of this device. I have attached screenshots of the app where this section is mentioned.
>>21358884 Hello, @paoliniluis, and Merry Christmas to all
I don't remember well (it was more than a year ago...), but I've opened it and see that there are remains of having soldered wires to CBU pins 13, 14, 15, and 16 (GND, 3.3V, TX1, and RX1, respectively), so I guess, I powered it from the USB to serial adapter used for flashing it.
I've checked that there are resistors between CBU's RX1 and TX1 and the MCU, so there's little risk of ruining the MCU's TX pin, which could happen if the programmer tries to output a different level than the MCU (it occurred to me with one of my TH08's...).
I'm attaching my actual autoexec.bat for this device:
Added after 17 [minutes]:
@p.kaczmarek2 :
I've found a misfunction in this device after upgrading OBK: voltage and current stopped working, and also the relay switched on by itself after switching off from the web interface.
I noticed this when updating to OpenBK7231N_1.17.808; then went back to previous versions I had in my HD and saw it worked again OK with OpenBK7231N_1.17.769.
Then, I started a dichotomic search to find out which was the version where the error started and found it was OpenBK7231N_1.17.796: with 795 everything went well but, after flashing 796, voltage and current values showed 0 while they were 230 V and 0.08 A with 795 (power was 0 for both, but probably it was because of its low value and/or resolution/rounding in 795).
In Github's releases page, changes for version 1.17.796 states: "support multiple RAW_TAC2121C_VCP channels for devices with 3 phases, etc (6e176a3)", so it seems the changes to RAW_TAC2121C_VCP don't go well for this single phase device... This doesn't directly explain the auto-resetting of the relay but could be a side effect.
This is the part of the autoexec.bat where I call RAW_TAC2121C_VCP, just in case the syntax should be changed to work with ver. 796:
// Measurements - Dpid 6 "phase_a" - channel RAW_TAC2121C_VCP -> 5,6,7
// TAC2121C VoltageCurrentPower Packet
// This will automatically set voltage, power and current
linkTuyaMCUOutputToChannel 6 RAW_TAC2121C_VCP
setChannelType 5 Voltage_div10
setChannelLabel 5 "Voltage"
setChannelType 6 Power
setChannelLabel 6 "Power"
setChannelType 7 Current_div1000
setChannelLabel 7 "Current"
EDIT: Checked it also with TOMPD-63-WiFi, with the same results: Version 1.17.796 showing V, I, P as 0, and reconnecting relay by itself when switching off from the web or even from the device. Version 1.17.795 works OK
Attachments:
TOMPD-63LW_autoexec.bat.txt(4.12 KB)
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There was indeed a bug. I've added a support for multiple VCP dpIDs for 3 phase meters, but the old behaviour of VCP, which was not working before because I forget that channel was unsigned integer. Here is my fix:
https://github.com/openshwprojects/OpenBK7231...mmit/f229e2c2047134b59e1e80c5e5ef3a05a214b62f Can you check whether the old VCP approach (without channel index in command) works again now?
The relay was auto-resetting because device tried to write voltage to channel 0 i guess. Current to 1, power to 2, etc.
>>21363783 Thanks, I'll try the fix ASAP.
I had already found after reading your post here that, if I added the voltage channel to the syntax of RAW_TAC2121C_VCP, in my case:
// Measurements - Dpid 6 "phase_a" - channel RAW_TAC2121C_VCP -> 5,6,7
// TAC2121C VoltageCurrentPower Packet
// This will automatically set voltage, power and current
linkTuyaMCUOutputToChannel 6 RAW_TAC2121C_VCP 5
setChannelType 5 Voltage_div10
setChannelLabel 5 "Voltage"
setChannelType 6 Power
setChannelLabel 6 "Power"
setChannelType 7 Current_div1000
setChannelLabel 7 "Current"
(added 5 at the end of linkTuyaMCUOutputToChannel 6 RAW_TAC2121C_VCP)
Then the problem with the switch dissapeared, and it started showing the correct voltage, but the values for power and current weren't good:
The first image is ver. 795 with "old" autoexec (without channel number at the end), the second, ver. 812 with old autoexec (shows 0 witha ll measurements), the third, ver. 812 with autoexec corrected (shows correct voltage, but higher power and current). The last one is to check if the new syntax works OK with old version (795), which apparently does, but it would be better for the new versions to work without the channel number after "linkTuyaMCUOutputToChannel 6 RAW_TAC2121C_VCP", to avoid having to update the autoexecs after updating versions. All of them are for TOMPD-63WIFI.
I'll check the behavior of the fix with these issues. Thanks again!
Added after 6 [hours] 27 [minutes]:
>>21363783 Ok, tried ver. 813 with the same results as 812...
Ver. 813 with "old" autoexec (without channel number afer linkTuyaMCUOutputToChannel 6 RAW_TAC2121C_VCP) gives 0 for voltage, current, and power, and restarts relay, while adding channel number after it gives correct value for voltage but wrong values for current and power (.4 A instead of .2 and 170W instead of 40; Im using a 40W lamp as load and old versions values match with the device's display), but relay doesn't restart when switching off
It's VCP, as in title, Voltage, Current, Power. You seem to have Voltage, Power, Current order. So Current value goes to Power and Power goes to Current.
>>21365272 True!! 🤦♂️
Its curious that it worked OK with old syntax and that it worked also well with old versions and the same autoexec 🤔
I'll try changing the order of the measurements, but now I'm away from home
CONCLUSIONS: 1.- With the old (single phase) syntax (no number after RAW_TAC2121C_VCP), it seems to put power and current in the corresponding type channel, regardless if channel order is V-C-P or V-P-C.
2.- With the new syntax (ready for multi phase), if V-C-P order is not respected, it shows current in the second channel and power in the third, regardless the channel type.
3.- This behaviour is good, in the sense older autoexecs with bad order will continue to work; in new autoexecs for multi-phase devices, it's not tolerant to errors in the order, so attention should be paid to put channels in the correct one (which shouldn't be a problem).
Many thanks to @p.kaczmarek2 for all his work!
EDIT 2: Just for the sake of testing it, I tried changing also the order of voltage with the "old" syntax. Works perfectly, so the "backwards compatible syntax" for single-phase devices is completely tolerant to channel order:
>>21615305 First, I'd try illuminating the screen from outside with a flashlight, as some LCDs can be seen this way well enough to navigate to the corresponding setting. This probably would work with the first version of this device ("black and white" LCD). I've tried with the colour one and it doesn't work, probably because it's OLED and not LCD.
If that doesn't work, after powering off and on (so the device is in a known state), I'd try navigating blindly to the setting (very easy in this case, as it's the first one), and change it. The sequence would be: long press of the set key, ten or more arrow up short presses (more than 10 seconds of light on), and long press of the set key again. Once this has worked, set it to the time you want (or permanently on, after 200 seconds).
Hi all! New version of TOMPD-63-LW with CBU module inside and color screen was purchased. OpenBeken v. 1.18.177 was flashed successfuly, but I have some questions:
1. Is it possible to fix default "Current" channel data? No load connected, but channel data are about 170, it doen't look like breakers's inside power consumption.
2. I can't understand how to calibrate VCP channels, division is only divider of channel data, but how to fix it to real measurement, for example with 40W bulb?
3. Is it possible to change channel 13 data?
P.S., @pkaczmarek2 , am I right, that it can be fixed only with addEventHandler OnChannelChange X setChannel Y $CHX+calbration because TuyaMCU doesn't exist internal channel calibration mechanism?
Hi!
I need to change this device's default power-on state to off, so that it will not turn on the load unless some kind of API request is received.
I'm new to the whole OBK thing.
Could you please advise if this is possible?
Hi, thank you for your awesome work!
I bought the device (color screen version), flashed it, all work.
But I've got a couple of question.
Is there a chance to get an indication of state? My red indicator blinks depending on load, but it would be useful if it is just on, when the relay is on.
And could be voltage/power indicator always on?
Thank you
✨ The discussion centers on the TOMZN TOMPD-63-LW Wifi Multi Function DIN power meter, specifically its compatibility and configuration with OpenBK firmware on the BK7231T platform. Users explored flashing the device with OpenBK, including safe UART data capture methods, backup procedures, and flashing techniques involving the TuyaMCU secondary MCU (HC89F0541). The device features dual relay switching for line and neutral, rated for 63A at 230V, 50/60Hz, with remote control, measurement of voltage, current, leakage current, power factor, and energy consumption, and configurable protection thresholds via the Tuya SmartLife app.
Key technical challenges included identifying UART pins, managing the TuyaMCU communication protocol, and mapping Tuya datapoints (dpIDs) to OpenBK channels. Users successfully extracted and analyzed dpIDs such as relay state (dpID 16), voltage/current/power (dpID 6), total energy (dpID 1), leakage current (dpID 15), alarms (dpID 9, 17, 18), and others. The community developed and refined autoexec.bat scripts to correctly interpret and display these datapoints, including handling raw data packets (RAW_TAC2121C_VCP), scaling factors, and channel labeling.
Firmware updates addressed issues like leakage current scaling, frequency display, and string termination for device identifiers. The device supports negative power detection (export), though the sign is not reported to the OpenBK interface. Users also discussed Tuya cloud API access for device shadow properties and the challenges of missing or write-only dpIDs (e.g., dpID 21, 101). The community contributed improved web interfaces and scripts for enhanced usability, including periodic state refresh commands (tuyaMcu_sendQueryState) to reduce data update latency from minutes to seconds.
Overall, the thread documents the collaborative reverse engineering, firmware customization, and integration of the TOMZN TOMPD-63-LW power meter with OpenBK, enabling local control and detailed monitoring beyond the original Tuya cloud ecosystem. Generated by the language model.
TL;DR: 63 A DIN-rail breaker logs 230 V/50 Hz data every 5–10 min, but “addRepeatingEvent 10 -1 tuyaMcu_sendQueryState” cuts it to 10 s [Elektroda, morgan_flint, post #21005072] “Flash first, you can always restore the 2 MB backup” [Elektroda, p.kaczmarek2, post #20693586]Why it matters: Faster, local data means no Tuya cloud and safer automation.
Remove the bridge and reboot. Total flashing time ≈90 s.
Which dpIDs give live voltage, current and power?
dpID 6 sends an 8-byte TAC2121C V-C-P packet. Map it with
linkTuyaMCUOutputToChannel 6 RAW_TAC2121C_VCP and assign channels Voltage_div10, Current_div1000, Power [Elektroda, p.kaczmarek2, post #21364564]
Voltage shows 0 V after updating to 1.17.796+. Fix?
Firmware ≥1.17.814 requires channel order V-C-P or an explicit index: linkTuyaMCUOutputToChannel 6 RAW_TAC2121C_VCP 5 (where 5 is your voltage channel). Wrong order swaps current/power and can reopen the relay [Elektroda, morgan_flint, post #21365381]
Relay closes again after I turn it off—why?
If dpID 6 writes to channel 0 (because of wrong VCP mapping) the firmware treats it as a power-on request and resets the relay. Correct the RAW_TAC2121C_VCP mapping or upgrade to 1.17.817 [Elektroda, p.kaczmarek2, post #21364564]
How often can I log measurements?
Factory MCU pushes V/I/P every 5 min and energy every 10 min [Elektroda, morgan_flint, post #21005072] Add addRepeatingEvent 10 -1 tuyaMcu_sendQueryState to autoexec.bat to poll every 10 s without Tuya cloud traffic.
Can I read power factor and grid frequency?
Yes. dpID 104 → PowerFactor_div1000, dpID 105 → Frequency_div10. Values update with each VCP frame and show 0.997 pf and 50.0 Hz under resistive load [Elektroda, morgan_flint, post #20845842]
Why does the prepaid energy box disappear on the custom HTML page?
It is hidden when dpID 11 (prepayment switch) is OFF. For LW units you can edit Settings_Prepaid_visibility() to keep it visible and load credit before enabling prepay [Elektroda, morgan_flint, post #21007376]
Edge-case: script crashes when dpID 21 is missing.
data.find(t=>t.id==21) returns undefined. Add a null check or default r=0 before processing to prevent the UI from breaking [Elektroda, Angel0fDeath, post #20990164]
How do I keep autoexec.bat after an OTA update?
BK7231 T builds ≤1.17.800 wipe LittleFS. Backup autoexec, update, then re-upload or wait for the upcoming safeguarded OTA that copies LittleFS automatically [Elektroda, p.kaczmarek2, post #21005116]
Does the breaker detect exported (negative) power?
Yes, reversing line/load shows –40 W on the LCD, but the Wi-Fi packet reports a positive value and kWh still increments, so exported energy is not accounted [Elektroda, morgan_flint, post #20853227]
Is the LCD readable outdoors?
Standard monochrome screen has high contrast; the newer coloured negative LCD dims under direct sun and when pressing the front keys, but angles are acceptable at 2 m distance [Elektroda, morgan_flint, post #21002417]
What’s the safest way to capture UART without mains risk?
Use a USB-Uart isolator (ADUM3160) and power the module from the adapter’s 3.3 V rail. “Doing capture on a mains-powered board without isolation is dangerous.” [Elektroda, p.kaczmarek2, post #20693586]
