All Questions
14
questions
5
votes
2
answers
1k
views
ESD protection on an isolated circuit
I'm currently working on an RS485 DMX circuit and am thinking about proper protective measures.
I've oriented myself on this question. I understand that galvanic isolation does not equal ESD ...
- 173
1
vote
0
answers
3k
views
How to interface a Raspberry Pi Pico to DMX / RDM
Years ago, I was looking at creating a stage DMX controller using AVR. Time moved on and the Raspberry Pi Pico has now been released. I'd like to revisit the project using a Raspberry Pi Pico, which ...
- 123
8
votes
2
answers
835
views
Effect of "wrong" driver with slightly long RS-485 stubs
I have a planned 250 kbit/sec, single-pair, 36-metre RS-485 installation where it is advantageous for wiring purposes if the stub lengths can be a little longer than optimal. There is a single almost-...
- 15k
0
votes
2
answers
394
views
Is it acceptable to have A & B wire at same voltage in RS485
I'm trying to implement DMX with a Raspberry Pi after reading this page: https://www.element14.com/community/groups/open-source-hardware/blog/2017/08/24/dmx-explained-dmx512-and-rs-485-protocol-detail-...
- 293
-1
votes
2
answers
96
views
What communication method shouild I use [closed]
So I wan to control a bunch of devices.
I though first of using RS485 but after some digging I figured out this might not work as I don't really have a pure daisy chain.
The configuration I would like ...
- 2,127
6
votes
1
answer
3k
views
Blowing out MAX485 transceiver
[Edit: revised my complete post]
I have a problem with a project I'm currently working on, and I would really appreciate some help.
I created 10pcs of 100W RGB LED modules that are communicating via ...
- 1,250
2
votes
1
answer
223
views
Do I have to use a MAX485 chip in front of an ATXMega microcontroller?
I'm doing a project which involves receiving DMX 512 information on an ATXmegaA3u microcontroller. I've successfully implemented the protocol using the onboard USART of the microcontroller. Basically, ...
- 129
0
votes
1
answer
63
views
Can I use SLIP on the same line as DMX?
I have a CAT 5 line with 12 DMX devices, each taking 4 channels.
I also have a CAT 5 line with 8 microcontrollers (ex. Arduinos). These controllers need to send back data, and require error detection....
- 103
2
votes
1
answer
390
views
choosing the right Opto isolator?
In the process of developing an RDM Compatible DMX receiver board (using a ATMEGA328) and I have been fortunate enough to come across kimliv's most informative answer concerning such a board;
DMX on ...
- 23
8
votes
2
answers
14k
views
What is the relationship between DMX and RS485? Are there any breaks in the protocol in relation to one another?
As far as the DMX is RS485 and at what points one moves away from the other? breaking the standard/protocol?
- 303
1
vote
2
answers
2k
views
PIC24F UART Rx Interrupt not firing
I am currently trying to write code for a 48 channel DMX controlled dimmer using a PIC24FJ32GA002. Using a scope I have confirmed that there is a DMX signal reaching the Rx pin of the UART which has ...
- 131
6
votes
1
answer
834
views
DMX512 packet issue (no break?)
I'm not sure if I'm reading this wrong or something, but this is a trace of the DMX packet that's coming from my USB-RS485 module then being converter to UART logic levels for my microcontroller.
...
- 1,315
3
votes
1
answer
18k
views
DMX on Arduino with RS485
I'm implementing DMX on Arduino. DMX uses the RS485 standard to communicate.
In the specifications of RS485 it notes that there is a positive line, a negative line and a ground line. If the positive ...
- 169
3
votes
2
answers
11k
views
How to de-couple DMX512 with opto-isolators?
I'd like to build a DMX512 device.
The problem I have is how to decouple the device from the bus. I decided to use opto-isolators, but how should I wire the diode part of the isolator?
Since I need ...
- 1,097