My French house is connected to the town gas network and I have a meter outside near the street. I’m aware of devices that can connect to the P1 ports of utility meters to report usage to Home Assistant. I can’t work out if my meter has such a port. It seems to have a pretty basic looking port on the side although it appears to only have two pins so doesn’t seem to be a P1 port which AFAIA is the same (?) as an RJ11 telephone connector.
I’ve attached photos of the meter and aforementioned port. There may be more under the cover but it doesn’t seem to come off particularly easily and I don’t want to damage it.
I think the meter is smart (despite its analogue display) so I’m hopeful it’s possible to extract the readings without having to resort to AI image processing.
I think I’ll give it a go and have ordered a wireless relay which I’ll try and use to send the pulses to an ESP32.
I’m a bit confused by what it means by “sending a pulse”. What is a pulse in this context? I was thinking if it’s just a dry contact that gets closed it will be easy to use this to trigger the relay. But the first post I linked seems to say it’s a sort of transistor, and I’d be afraid of sending a voltage into the meter for risk of frying something inside it.
Can anyone with more electronics knowledge than me suggest the best approach?
The french community post I linked just has the guy linking up the relay transmitter with a 9v battery to the meter port in series, whilst the blog post seems a lot more complex. There is a community comment where one user reports thinking they may have fried their meter. Any ideas?
I am not sure what you read but ESP is overkill, buy a simple ‘button’ (any protocol) and have it short-cut the connection via the gazpar cables instead of pressing the button
I already have an esp32 measuring my electricity usage so was planning on using the same device for the gas. But it’s not in range of the gas meter so am planning on using a wireless relay like the following to act as the “button”.
My main uncertainty is around wiring the relay’s transmitter to the gas meter. The example I read has it wired in series with a 9v battery but I want to make sure I won’t harm anything inside the meter with the battery’s voltage
I guess (?) the 9v is for signal strength, it still only does a dry contact with each 10l o fgas, wiring it to a (e.g. ikea) button will set you back 5-15 eur depending on protocol
I just resurrecting this topic as I’d like to get to the bottom of a problem I’m having.
I have my meter set up as described above, using a wireless relay to transmit the pulses to an ESP32. The relay transmitter is wired in series with the meter with 3 AA batteries for power as shown below
Here is the ESP32 code for measusing the pulses, with the relay receiver being connected to pin 34 of the ESP32:
- platform: pulse_meter
name: "Gas Usage"
id: gas_usage
internal_filter: 75ms
unit_of_measurement: "m³/h"
icon: mdi:fire
timeout: 5min
filters:
- multiply: 0.6 # 60mins * (100th of a m³)
pin:
number: GPIO34
mode:
input: true
pulldown: true
total:
name: "Gas Meter Total"
id: gas_total
icon: mdi:meter-gas
accuracy_decimals: 2
unit_of_measurement: "m³"
state_class: total_increasing
device_class: gas
filters:
- multiply: 0.01 # 100 x 10L in a m³
When I test this simply by completing the circuit by contacting the two ends that go to the meter, the pulse is received correctly by the ESP32. However when actually connected to the meter only a few pulses are being received when gas is being consumed. Some seem to be getting through but the majority are not.
I tried playing with the internal_filter setting but it makes no difference.
To rule out the meter itself being broken I instead tried using a Zigbee button with the meter contacts wired to the button. This happens to work perfectly and all pulses are received as events from the button in HomeAssistant.
I’d like to solve the issue of why the ESP32 solution is not working though.
Can anyone shed any light on why the pulses are not being detected by my simple wireless transmitter circuit? If the meter port is just a simple dry contact as seems to be the case from the searches I’ve performed then it should work as expected. Could the componentry inside the meter that does the “pulsing” cause my transmitter circuit to not work as expected?
