Hi,
I am about to use an LMX9820 for connecting it to PDA or mobile, by documentation this should be piece of cake - but dont works yet, please help if u can.
The facts and suggested solutions of problem:
Built circuit:
1. I have LMX powered properly 3.3V
2. I have a simple 40 mm length wire as antenna just for testing period (an other module worked fine using this)
3. (as the National FAQ suggested crystal problem is feasible) The 12Mhz crystal was tried with 2x10pF, 2x12pF, 2x8.2pF and other capacitor combinations - but failed to connect.
Suggestions:
1. the LMX9820 automatically after booting up is discoverable
2. and automatically responses to discoveries (eg. from PDA)
3. and automatically establishes connection offering serial port profile
Problems:
1. I cannot discover it using my PDA
2. The HostWU is blinking just after bootup, but found nowhere that LMX should do that
3. (this is marginal at the moment) the UART is connected to a microcontrollet (PIC) and the LMX saqys 0x00 0x08 after every reset - what is weird also
Suggestions for problem solution:
1. I think that the crystal and capacitors (the figure showed that above) are not properly working together to be in the required 15-20 ppm - How should I select proper setting?
2. Next thing what can be weak is the antenna: should I use some elements to connect the antena? (eg capacitor)
3. for the HOSTWU and UART messages I dont even have idea... if anyone knows something please post it.
Thanks
I am about to use an LMX9820 for connecting it to PDA or mobile, by documentation this should be piece of cake - but dont works yet, please help if u can.
The facts and suggested solutions of problem:
Built circuit:
1. I have LMX powered properly 3.3V
2. I have a simple 40 mm length wire as antenna just for testing period (an other module worked fine using this)
3. (as the National FAQ suggested crystal problem is feasible) The 12Mhz crystal was tried with 2x10pF, 2x12pF, 2x8.2pF and other capacitor combinations - but failed to connect.
Suggestions:
1. the LMX9820 automatically after booting up is discoverable
2. and automatically responses to discoveries (eg. from PDA)
3. and automatically establishes connection offering serial port profile
Problems:
1. I cannot discover it using my PDA
2. The HostWU is blinking just after bootup, but found nowhere that LMX should do that
3. (this is marginal at the moment) the UART is connected to a microcontrollet (PIC) and the LMX saqys 0x00 0x08 after every reset - what is weird also
Suggestions for problem solution:
1. I think that the crystal and capacitors (the figure showed that above) are not properly working together to be in the required 15-20 ppm - How should I select proper setting?
2. Next thing what can be weak is the antenna: should I use some elements to connect the antena? (eg capacitor)
3. for the HOSTWU and UART messages I dont even have idea... if anyone knows something please post it.
Thanks
