Yet another DYI Plato scale

[mper]

Yes, its the same pins. 4k7 as pullup as normal! I have not updated the schema yet.

 

[Lalo_uy]

Is the DS18B20 connected the same way:
GND ---> GND
VCC ---> 3V3
DQ ---> D7
And a 4k7 between DQ and VCC "as usual" ?

4k7 is “usual” on 5v vcc. On 3v you are better off with 3k3.
Lower pullup get better noise inmunity. I go as low as 820 ohms on long lines.

 

[mper]

4k7 is “usual” on 5v vcc. On 3v you are better off with 3k3.
Lower pullup get better noise inmunity. I go as low as 820 ohms on long lines.

Thanks, will try that instead

 

[beren]

Nice to find this thread. I has been experimentig with hx711 and load cells to weight the fermenter.
I want to find the delta as co2 exit to calculate the amount of alcohol and then the Plato.
As you mention time drift make it almost impossible.

Is evaporation not large enough to make a difference?

 

[Lalo_uy]

After some chemistry calculations, for every 40g of alcohol 44g of co2 are produced. Some of it remains in the liquid and in head space. But the co2 that goes out in the bubbles leave the system, the weight goes down.

 

[mper]

After some chemistry calculations, for every 40g of alcohol 44g of co2 are produced. Some of it remains in the liquid and in head space. But the co2 that goes out in the bubbles leave the system, the weight goes down.

So if you have a 23 liter batch (make that 23 kg for easy math) and the alcohol content is 5% that would mean that the alcohol would weigh 23*0,05=1,15kg and the co2 weight would be 1,265kg. Would the weight then be reduced by 1.265 kg or the difference between 1,15 and 1,265 (165 grams) ?

 

[Lalo_uy]

So if you have a 23 liter batch (make that 23 kg for easy math) and the alcohol content is 5% that would mean that the alcohol would weigh 23*0,05=1,15kg and the co2 weight would be 1,265kg. Would the weight then be reduced by 1.265 kg or the difference between 1,15 and 1,265 (165 grams) ?

1.265g - the co2 inside the fermenter. You know the exact weight cos you know the OD.

 

[mper]

1.265g - the co2 inside the fermenter. You know the exact weight cos you know the OD.

Well this might be worth testing in practice. I will build another scale base and put that under my fermenter to collect some data.

 

[mper]

I have been running Kegmon v0.6.0beta1 with ESP32-s2 for a few days now. Stable and no big issues.

When I first built the unit with D1 mini, I connected VDD on DHT22 to 3V3 according to the schematic at that time.
Yesterday, I changed DHT22's VDD connection to JP1.5/D6 as in the latest schematic.
ESP32-s2 did not recognize any temp sensor unless I flashed firmware via Web interface again. Then it worked for some time before temp sensor was gone again (Web interface/ MQTT).
Today, I connected VDD back to 3V3. All ok.

I wonder if the voltage level from ESP32-s2 I/O's is on the edge to be too low for the DHT22 (Rated 3.3 - 6V). Sorry, forgot to measure.
DHT22 current (1-1.5mA) should be ok.
Any voltage differences on the I/O ports for D1 mini vs ESP32-s2 maybe?

Is likely that there is not enough power from a GPIO pin towards the DHT22, I modified my build with an transistor to ensure that there is enough power and I steer the transistor with the GPIO pin.

I added an CAT6 2m cable and there was no drop in voltage over that distance so its probably a power issue (Amp) and the latest beta worked with both an esp8266 and esp32s2

I have asked a friend of mine to make a PCB and look over the schema. So we will see what he comes up with, he is much better at the electronics side than me.