Hi @beegee
Thanks for this help. I still have a few questions and I would be grateful if you could help me further.
I assume I can connect a push button to the RX1 and GND pins. Will this need a pull-up resistor?
Will this interfere with the serial connection from PlatformIO?
What pin number will this appear as in the code?
The example code with the Arduino button library polls the button pin from the main loop. Is there a wat to get an interrupt instead?
The 18001 buzzer I use at the moment connects to pin WB_IO3.
I assume this will change with the new 19003 base?
Hi @Alangward
Just realized that the RAK12500 is connected to both UART1 (RX1/TX1) and I2C, so you cannot use any of the pins for a button. Sorry, I complete forgot about that.
Two possible solutions:
a) use the RAK1910 (RX1/TX1 only) and use SCL or SDA for a button
b) use the RAK5005-O base board instead of the RAK19003.
We have used the RAK 1910 in the past. With the RAK 12500 I am able to turn it off until a few seconds before we need a fix - using the API. Is that possible with 1910?
Hi Allan,
It depends on the view to the sky. Unobstructed view it takes 15 seconds after cold start. In my front yard (antenna sees only half of the sky) it can take 30 second
Hi,
Looking at the device documentation I found this:
Fast location fix.
29 s from cold start to first fix.
1 s from hot start
The 29s correlates well with what you say above. But it implies there is a warm start option, which presumably draws less current than fully on. Do you know how I can select/deselect that mode.
Thanks
Alan
The warm start requires the GNSS chip to be kept powered up. So far I didn’t find out how to put the RAK1910 into a mode that supports that. The RAK12500 library has functions for power saving modes, but in my tests it was rather disappointing, power consumption didn’t lower as much as expected. Don’t have values recorded, I gave up on that option quite fast.
My experiments with the 12500 were quite successful. When it was on it was drawing about 50mA, When I turned it off that dropped to 5mA for the entire board. I set the timer so that it woke up a few seconds before the main loop activated.
Will the GNSS library work with the 1910?
Hi @beegee
I assumed the 5mA was because the GPS was in standby and I’m OK with that . How can I find out how to put the 1910 in warm standby mode so that will get a fix in a few seconds?
Hi @beegee
I had already discovered that document. I have also downloaded
u-blox 7 Receiver Description Including Protocol Specification V14.
I’m a little worried that this device appears to be ‘end-of-life’ on the u-blox web-site.
So I’m wondering how long you will be able to maintain supplies of the 1910. If our design is critically dependent on it we may run into problems in the future.
Anyway, I see it supports the UBX protocol as well as NMEA so I intend to investigate whether this gives us more control. I’ll let you know how I get on.
Thanks
Alan
I am thinking about a hardware change on the RAK12500. Having the RX/TX disconnected and a solder jumper for people who needs serial communication. But that is of course nothing that will be available fast.
Hi,
I have received and assembled this base board with the RAK 18001 buzzer and the RAK12500 GPS. Everything works fine except that I cannot get the buzzer to work - I assume I am using the wrong pin - I have tried changing it with no improvement.
Thanks
Alan
One thing we found about the Tone() function in Arduino. It can happen that the IO is staying on HIGH level after the tone was played. You need to use digitalWrite(IO, LOW) after finishing to play a tone.
