Re: raspberry pi for packet radio


John G8BPQ
 

Pascal,
 
The PI GPIO pins operate at 3.3 volts, and the PI is likely to be damaged by applying 5 volts from a normal TTL port. You will need a level converter on the TNC to PI lead. I used a simple resistor divider. Most TTL inputs are happy with the lower voltage from the PI.
Normally the PI linux kernel allocates the serial port as a console. You need to disable this to use it for packet.
I've used the linux ax.25 and netrom code, and the linux node. I haven't tried jnos.
 
73,
John
 


From: Raspberry_Pi_4-Ham_RADIO@... [mailto:Raspberry_Pi_4-Ham_RADIO@...] On Behalf Of ve2hom
Sent: 08 September 2012 18:30
To: Raspberry_Pi_4-Ham_RADIO@...
Subject: [Raspberry_Pi_4-Ham_RADIO] raspberry pi for packet radio

 

Hello all,
I have a raspberry pi and I want to use it for making a packet radio server. I have think to use jnos2 and I want to connect it with my mfj-1270c tnc. This one have a ttl port on the back, can I connect it directly to the GPIO port of the raspberry pi?

Other question, if I try to use a usb to serial adaptor when I attach the port an arror says "protocol error", don't know if it's because jnos don't like usb serial port. Any clue?

Tnx
73' de Pascal
ve2hom

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