T
treez
Guest
Hi
We are doing DALI comms with our LED drivers as in the schematic on page 3 of AN1465….
https://ww1.microchip.com/downloads/en/AppNotes/01465A.pdf
The waveform at the RX pin of the micro is as in the attached. (as you can see, rise time is a little slow unfortunately, due to the opto capacitance and pullup resistor)
Many times either the TX , or the RX, or both, (we are not sure which) is not working. Do you think the problem may lie in the slow rise time of the signal ? (as shown in the attached) If so we will reduce the pullup resistor value....but one of the products is very power sensitive , and there isnt scope to reduce it by much.
We send config data to the driver via DALI when in production, and the driver sends back acknowledge data, to confirm what data it “thought” it got sent……..but this RX/TX scheme often fails, ….some units take 4 or 5 go’s before the config process comes up as OK. Its really slowing up our production.
Does anybody know what may be causing this?
The Softy who wrote the config software is no longer with us.
Sometimes when config fails, the driver fails to send back acknowledge data, sometimes it sends back the ACK's but it still fails.....all the units will eventually config correctly, but it often takes several goes.
We are doing DALI comms with our LED drivers as in the schematic on page 3 of AN1465….
https://ww1.microchip.com/downloads/en/AppNotes/01465A.pdf
The waveform at the RX pin of the micro is as in the attached. (as you can see, rise time is a little slow unfortunately, due to the opto capacitance and pullup resistor)
Many times either the TX , or the RX, or both, (we are not sure which) is not working. Do you think the problem may lie in the slow rise time of the signal ? (as shown in the attached) If so we will reduce the pullup resistor value....but one of the products is very power sensitive , and there isnt scope to reduce it by much.
We send config data to the driver via DALI when in production, and the driver sends back acknowledge data, to confirm what data it “thought” it got sent……..but this RX/TX scheme often fails, ….some units take 4 or 5 go’s before the config process comes up as OK. Its really slowing up our production.
Does anybody know what may be causing this?
The Softy who wrote the config software is no longer with us.
Sometimes when config fails, the driver fails to send back acknowledge data, sometimes it sends back the ACK's but it still fails.....all the units will eventually config correctly, but it often takes several goes.