A quick note for anyone wanting to add in humidity monitoring.
The low power emonTX has sketches for using a DHT22 humidity monitor, however I couldn't;t find any instructions as to how to actually connect it to the board.
If you are not going to use the DS18B20 temperature sensor, then you could simply wire it though that jack, and change the sketches to use DHTPIN 4, however I wanted to keep that port clear for additional temperature monitoring so looking through the design and board layouts, i could see that the Pulse monitoring jack used DHTPIN 3 (labeled as IRQ on the circuit board) here's what I did:
I) Soldered up the board with just the components needed for the low power emontx
2) Put a jack socket in to the pulse monitoring position
3) Added a 4k7 resistor between IRQ and power on the CT2 pin out area
4) Joined the 5V to the centre on the solder pad just beneath the pulse counting jack - this therefore uses the switched power from when Pin 7 goes high.
5) IMPORTANT: Because of the way the bard is confiured the sensor leads need to be connected to the jack in this order:
Tip: +5V Vdd (Power - pin 1 on sensor)
Ring / Middle: DQ (dataline - pin 2 on Sensor)
Sleeve: GND (Ground - pin 4 on sensor)
(pin 3 on the sensor isn't used - Null)
6) Altered the sketch to define DHTPIN 3
7) in the read loop changed the delay to delay(2000) to give the dht a chance to respond (it's slow:) )
Pictures below:
Re: Using 'Pulse' Jack for DHT22 Hmidity and Temperature Monitoring on Low Power emonTX
Would this work with a board that is already soldered up for Voltage and current measuring? I would like to measure all three together if possible.
Re: Using 'Pulse' Jack for DHT22 Hmidity and Temperature Monitoring on Low Power emonTX
I don't see why not.