How to use two sevenseg HT16K33s to display two sensors (with C->F conversion)?

[markfickett]

I have two Adafruit HT16K33 I2C backpacks wired up to a HUZZAH ESP8266 dev board, successfully reading from two MAX6675 Thermocouple breakouts.

I'd like to show one thermocouple's value on each 7-segment display (as well as sending the values to HA for logging). However, I'm having trouble:

• showing a sensor value on the display
• showing anything on the second display

One display has the default I2C address of 0x70, the other has A0 shorted so it uses 0x71. It's the second one with A0 shorted that is actually showing something.

Some things that are working:

• Compiling with USE_DISPLAY and USE_DISPLAY_SEVENSEG and (for the thermocouples) USE_MAX31855
• Custom DisplayText commands like DisplayText f98.6 listed in xdsp_11_sevenseg.ino and updated in this PR
• Sensor data is showing like this in the console: tele/tasmota_30EF0B/SENSOR = {"Time":"2023-12-11T00:54:59","MAX31855-0":{"Temperature":22.8,"ReferenceTemperature":23.6,"Error":0},"MAX31855-1":{"Temperature":22.5,"ReferenceTemperature":22.9,"Error":0},"TempUnit":"C"} . And I can see both thermocouple values in HomeAssistant.

Some other resources I've looked at:

• Common-anode 7-segment to show variables discussion, the %value% style commands are not working for me
• Project report of using two I2C e-paper displays but I'm not sure how it would map to what I'm doing if at all
• 7-segment specific commands which I gather are different for TM1650 and other related 7-segment displays
• Resource files for displays I haven't really dug into these, hoping I can get by with more default settings
• Docs ticket requesting documentation for these I2C displays

Here's how it looks:

Thanks in advance for any help!

[barbudor]

I don't think Tasmota can manage 2 displays simultaneously
At least not natively
You probably have to write a separated driver for the other one using either Scripting-Language or Berry (later available only on ESP32 family)

[sfromis]

While I have no experience with this, the comments clearly suggest that up to 8 seven-segment displays are supported, with a command code in DisplayText to select which display is addressed.
https://github.com/arendst/Tasmota/blob/development/tasmota/my_user_config.h#L742-L750

[markfickett]

Thanks, so it looks like the default 0x70 address is not getting seen because MTX_ADDRESS1 is 0x71, and if I short my 2nd display to use 0x74 then I should be able to use DisplayText [y2]text with it. I'll give that a shot.

[markfickett]

Confirmed that after shorting the other display so it uses 0x74, I can address it with commands like DisplayText [y1]f91.4 (and the original one with 0x71 I can address with DisplayText [y0]f72.1).

Here's how it looks:

[sfromis]

Assuming that the Tasmota support for multiple HTK16K33 works as suggested, making suggestions for how to do things differently gets hard without any details of what you're actually trying, like how you tried addressing the 2nd display, and what you mean by opaque statements like "the %value% style commands are not working for me".

For 7-segment displays, I do not think that you should even look in the direction of how it works for e-paper displays or using display descriptor files, as the simple segment displays do not provide such capabilities.

When it comes to C/F, Tasmota does provide SetOption8 to select which units temperatures are to be represented as.

[markfickett]

It probably sounds opaque because I'm really not sure what I should be doing (: but thanks for taking a look.

What I'm looking for is a way to get the sensor value and put it into a DisplayText command for my seven segment display. This other discussion had suggested some rules like ON tele-BME280#Temperature DO DisplayText [....]Temp: %value% C ENDON which is where I got the %value% from, but I haven't figured out how to make that work. If there's documentation for using variables in rules and you could point me to it, or if you would be willing to help with an example that fits my sensors, that would be awesome.

[sfromis]

In ON tele-BME280#Temperature DO DisplayText [....]Temp: %value% C ENDON
%value% is simply the value from the trigger, in this case the temperature value, as mentioned here; scroll down for more available variables.

What you can do in triggers is here; pay special attention to the part about JSON-based triggers, where you have to match the object levels in the JSON you already get for the sensors, similar to the example with BME280.

When you create a rule set, you need to make sure to also enable the rule set, both of this is using the Rule command.

More generally, it works better if you post exactly what/how you're trying to make it work, as this makes it easier to spot details which were off. And with rules, the thing is that you can expect nothing to work, and no error messages, until you get every detail right.

[markfickett]

Thanks, the Rule docs were what I needed! I didn't realize that %value% was something specific to rules, now I see how that works.

The ruleset I am using for now is:

Rule1
  ON tele-MAX31855-1#Temperature$!null DO DisplayText[y0]f%value% ENDON
  ON tele-MAX31855-1#Error>0 DO Backlog DisplayText[y0x0]r121[x1]r80[x2]r0[x3]r80[x4]r0 ; Delay 1 ; DisplayText[y0]%value% ENDON
  ON tele-MAX31855-0#Temperature$!null DO DisplayText[y1]f%value% ENDON
  ON tele-MAX31855-0#Error>0 DO Backlog DisplayText[y1x0]r121[x1]r80[x2]r0[x3]r80[x4]r0 ; Delay 1 ; DisplayText[y1]%value% ENDON
BREAK

And SetOption8 1 did the trick for C->F, thanks. Initially I had added the sensors in HomeAssistant when they were in C but HA converted them to F; then when I switched Tasmota to F my values in HA got messed up. But deleting the HA entity and letting HA autodiscover it again let it pick up the right units.

[lalo-uy]

This are my rules to display 2 termps on a single 8 digit display: First keep value on var1 rounded up. ON Tele-DS18B20-1#Temperature DO Backlog Var1 %value% ; Add1 0.5; ENDON Then display secon temp with deg symbol and the first rounded value wit the same symbol ON Tele-DS18B20-2#Temperature DO Backlog DisplayText %value%^ ;DisplayNumberNC %Var1%,4,0,3; Displaytextnc ^,7; ENDON El El lun, 11 dic. 2023 a la(s) 12:08, sfromis ***@***.***> escribió:

…

In ON tele-BME280#Temperature DO DisplayText [....]Temp: %value% C ENDON %value% is simply the value from the trigger, in this case the temperature value, as mentioned here <https://tasmota.github.io/docs/Rules/#rule-command>; scroll down for more available variables. What you can do in triggers is here <https://tasmota.github.io/docs/Rules/#rule-trigger>; pay special attention to the part about JSON-based triggers, where you have to match the object levels in the JSON you already get for the sensors, similar to the example with BME280. When you create a rule set, you need to make sure to also enable the rule set, both of this is using the Rule command <https://tasmota.github.io/docs/Commands/#rules>. More generally, it works better if you post exactly what/how you're trying to make it work, as this makes it easier to spot details which were off. And with rules, the thing is that you can expect nothing to work, and no error messages, until you get every detail right. — Reply to this email directly, view it on GitHub <#20202 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ACXBW4OWV7KXQSZNV2USQCTYI4OXXAVCNFSM6AAAAABAO54TC2VHI2DSMVQWIX3LMV43SRDJONRXK43TNFXW4Q3PNVWWK3TUHM3TQMRRGA3DE> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[markfickett]

Thanks for the example rules!