Lynxmotion Tech Support

I am using a Parallax Basic Stamp BS2sx and an analogue-digital converter AD0832 to digitise to 8 bits the elevation angle from a CrossBow inclinometer. I used a notebook with XP Windows operating system and the program worked perfectly.

However, when I connected a set of XStream-PKG radio modems of 2.4G Hz at 9600 bps with no flow control at a short distance of not more than 1m, a dialogue box told me that "Basic Stamp cannot be found".

I thought the wireless modem is transparent for serial communication. Please help. Thanks.

Daniel Chia

well transparent is sort of correct except that it doesn't really deal with latency. because the data needs to be encoded and decoded there is a delay between when your PC sends the data and when it shows up on the other end, a delay that does not exist in a hard wired connection. you will see the delay is doubled when you consider a program sends a command byte and then expects a reply since the reply also needs to be encoded and decoded. unfortunately many of the basic modules require a fairly tight timing requirement for programming and while high latency connections like wireless and cheap USB-to-serial adapters may work for normal communications they are not suitable for programming.

Thanks for your reply.

If I were to replace BS2sx by BasicX24, will it improve the latency so that I can retreive the data wirelessly? If BasicX24 is not suitable, what is a good microprocessor and radio modem that will help me to obtain the data wirelessly?

Thank you.

Daniel Chia

It is the radio link causing the latency not the processor module. Having said that though some combinations of module and download software may be less affected by, or perhaps I should say more tolerant of, higher latency connections. I don't have any particular recommendations other than to ask if you actually need to do program updates wirelessly... suggesting you do your development using a wired connection and once you have the program worked out go back to a wireless connection.