Hi there all,
i just put my new finish pulse counter in production :-)
...but 2 battery was finish (total 2,68 V) after 4 days
I wonder if i can put 3 batterys on the emonTX ???
How much emonTX need to work ? over 2,7 V ?
Thanks all
Denis
3 X 1,5 AA batterys on emonTX
Submitted by Guest on Tue, 14/02/2012 - 17:22»
Re: 3 X 1,5 AA batterys on emonTX
mine is powered with 3x 1.5v
no problems so far, but maybe someone has more experience with it.
Re: 3 X 1,5 AA batterys on emonTX
To get a long battery life (several months) you need to put the emonTX to sleep between measurements. The emontx code comes with this integrated. Unfortunatly sleep mode disables the atmega timers and if you want to measure power from pulses you need to have the timer enabled and so for power calculation from length of time between pulses the atmega cant be put in sleep mode. Do you want to measure power or is energy accumulation enough?
Re: 3 X 1,5 AA batterys on emonTX
I must misure all 2 :-)
...is for my solar PV system
I use it with the last 2 pulses in order to have the last power
...then i have make a loop delay every 10 minutes and i allready put
the RF in sleep mode in this time (rf12_sleep(RF12_SLEEP);
After 10 min i wakeup the RF (rf12_sleep(RF12_WAKEUP); and i send the last 2 pulse calc
and the total of pulse in this 10 minutes.
10 minutes is a lot of time for the loop ... but :-(
I have tryed to use the Sleepy::loseSomeTime(60000);
but when interrupt event the emonTX is blocked.
Maybe i must put the omniboot firmware.
Do you know maybe witch pin i must use to link the emonTX with emonBase in order to update the omniboot please ?
Thanks a lot
Denis
Re: 3 X 1,5 AA batterys on emonTX
Sorry ... another question Trystan
...because i have not the phototransistor TSL257, i have take out the photoresistor from the emonGLCD (LDR)
and i use it on the emonTX for pulse reader .. and is work :-)
Now the question is ... who it more power ... the photoresistor or the phototransistor ?
Thanks again
Denis
Re: 3 X 1,5 AA batterys on emonTX
The emonTx should not be powered through the battery input (connections on the left hand side) with more than 3.7V, as this is the maximum voltage the RFM12B can handle. To increase battery life the power from the battery terminals does not go through the MCP1702 3.3V voltage regulator. 3 x 1.5V AA is 4.5V (potentiall 5V), this is higher than the datasheet maixum for the RFM12B. If you want to power the emonTx with greater than 3.7V you should connect the power to the PWR and GND pins, this way the power will be regulated down by the MCP1702 down to 3.3V.
In the past I have ran a RFM12B at 5V (for a short period) and is didnt seem to do any harm, but I don't recomend it!
Re: 3 X 1,5 AA batterys on emonTX
Ok... thanks a lot Glyn
About the second question please ??? do you have an idea ?
Thanks again
Denis
Re: 3 X 1,5 AA batterys on emonTX
No it won't work. The LDR will change it's resistance depending on light level. At least a voltage divider circuit will b e required to change this change in resistance into a change in voltage. This will be a analog change in voltage wich will require using an ADC input, unelss an external amp is used. Also I'm not sure the LDR will be sensitive enough and react fast enough to detect a pulse.
Re: 3 X 1,5 AA batterys on emonTX
No Glyn... maybe i have wronk write the post
...the ldr is work, i uset it allready about one week, and is work great, but my question is
-in order to consum less power, is better to use the ldr or the transistor TLS257 ?
Maybe the unique thinks is that the ldr is too sensible i'll change the 10k resistor (R8)
with some else
Denis