Updating XBee firmware on the cheap
sylvie369
Posts: 1,622
I love figuring this stuff out. I've got 5 XBees (Series 1), and I've been wanting to play with the Analog -> PWM line passing for quite a while. I tried setting it up, and discovered that the old firmware version I had on them didn't have the necessary commands. They're mounted on Selmaware XBee SIP boards, and I've been using a Propplug with the X-CTU software to change settings on them, but it doesn't have the DTR connection necessary to upgrade the firmware.
So I did a little reading of the XBee manual to make sure I knew which connections were needed, then took a look around at what I have on hand. About two years ago I built two of these little RS-1 Max232 adapters for converting between TTL and RS-232 (man, I'm sure I didn't pay $18 for them, though):
www.awce.com/rs1.htm
That looked like what I needed, so I wired it up to an XBee with one of the SIP boards and a 5V power supply. I had to run a wire from pin 9 of the XBee (DTR) to the CT pin of the 232 converter: the rest of the pins I needed (Vin, Vss, TX, RX, RTS) are already brought out from the SIP board header. After a little false start due to one wire in the wrong place, I started it up, and X-CTU was able to find the XBee just like if I'd had it connected through the Propplug. Then I went to the Modem Configuration tab, and read the current firmware. No problem. Then the moment of truth - I picked the most recent version of the firmware and clicked on "Write", and sure enough, it happily updated the firmware. I did it with the other 4 XBees, and they all went smoothly.
I don't have time now to mess with the ADC stuff, but I'm pretty happy to have been able to figure this out, and to do it with parts I have on hand already.
(Edit: ) Oh, of course I should have done something to bring the voltage from that CT pin -> XBee pin 9 down to 3.3 volts (a little voltage divider, I imagine). I didn't. No damage, and the circuit worked, but the connections directly to the XBee pins really should not come directly from a 5V TTL output.
Post Edited (sylvie369) : 12/25/2008 5:30:35 PM GMT
So I did a little reading of the XBee manual to make sure I knew which connections were needed, then took a look around at what I have on hand. About two years ago I built two of these little RS-1 Max232 adapters for converting between TTL and RS-232 (man, I'm sure I didn't pay $18 for them, though):
www.awce.com/rs1.htm
That looked like what I needed, so I wired it up to an XBee with one of the SIP boards and a 5V power supply. I had to run a wire from pin 9 of the XBee (DTR) to the CT pin of the 232 converter: the rest of the pins I needed (Vin, Vss, TX, RX, RTS) are already brought out from the SIP board header. After a little false start due to one wire in the wrong place, I started it up, and X-CTU was able to find the XBee just like if I'd had it connected through the Propplug. Then I went to the Modem Configuration tab, and read the current firmware. No problem. Then the moment of truth - I picked the most recent version of the firmware and clicked on "Write", and sure enough, it happily updated the firmware. I did it with the other 4 XBees, and they all went smoothly.
I don't have time now to mess with the ADC stuff, but I'm pretty happy to have been able to figure this out, and to do it with parts I have on hand already.
(Edit: ) Oh, of course I should have done something to bring the voltage from that CT pin -> XBee pin 9 down to 3.3 volts (a little voltage divider, I imagine). I didn't. No damage, and the circuit worked, but the connections directly to the XBee pins really should not come directly from a 5V TTL output.
Post Edited (sylvie369) : 12/25/2008 5:30:35 PM GMT