Hello everyone,
I’d like to use an external ultrasonic sensor (Maxbotix MB7389, TTL output, 3v3, peak current 49mA) with CubeCell. It would read the sensor, transmit via LoRa and then go to sleep for 2 minutes. This would include shutting off the sensor to save power.
Can I use the Vext pin to power on the ultrasonic sensor and then shut down again before going to sleep?
Which pin would you suggest to use for TTL?
best regards, Martin
You are using the Dev-Board?
TTL means data input/output via UART?
Yes, I am using the dev-board.
I had a working prototype using an arduino pro mini. I used the library softwareserialread to read the sensor (TTL or RSR232, both is supported by the sensor). I basically would like to do the same here.
@Supporter hi. I have same question.
How can I power my sensors to disconnect the power when board are sleeping.
the answer is in the examples.
You can activate Vext:
pinMode(Vext, OUTPUT);
digitalWrite(Vext, LOW);
delay(500);
and deactivate Vext:
digitalWrite(Vext, HIGH);TTL means serial with an voltage level of 3.3 or 5v?
Or a other protocoll?
The asr6501only has one uart which is reserved for at commads.
Pleaee wait for new products using the asr6502 which has 2 uarts. With the asr6502 it will be easy to add a serial device like your sensor or a gps
Exactly, its just serial with voltage level 3.3v. Sorry this wasnt clear.
So it’s not possible to use the internal uart at all? I don’t understand why there are rx/tx pins on the dev-board then. Maybe you can help me with this.
Power the sensor from the Vext pin. When entering sleep the library turns off Vext. But on awake you need to turn it on yourself.
I discovered however in awake mode .Vext some how gets turned back on again after i set it to off when connecting a GPS module and noticed the GPS moule LED continued to flash when i had powered down Vext.
So if you need to save power as soon as you have read from the sensor, while still awake. Use a flag such as
OnVext=false;
and in the main loop
if (OnVext==false){
pinMode(Vext, OUTPUT);
digitalWrite(Vext,HIGH); // turn on power to the sensor
}
Because reading the battery voltage or using the Lora module tx or rx the library switches on the Vext and does not turn it off again after.
So constantly checking in the main loop that we need it off. Turns it off after being left on.