CCS C Software and Maintenance Offers
FAQFAQ   FAQForum Help   FAQOfficial CCS Support   SearchSearch  RegisterRegister 

ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

CCS does not monitor this forum on a regular basis.

Please do not post bug Reports on this forum. Send them to support@ccsinfo.com

usb to rs485 full duplex communication
Goto page Previous  1, 2, 3
 
Post new topic   Reply to topic    CCS Forum Index -> General CCS C Discussion
View previous topic :: View next topic  
Author Message
temtronic



Joined: 01 Jul 2010
Posts: 7349
Location: Greensville,Ontario

View user's profile Send private message

PostPosted: Fri Mar 20, 2020 2:34 pm     Reply with quote

More puzzle... in the post with 4 'onedrive pictures' there are 2 with a USB adapter. It has USB connector, a 28pin IC, an 8 pin (on bottom) and a 4 pin vertical header.
The top of the PCB, near the connector says USB......85. I think it might be a USB to RS485 adapter. Another picture shows it connected to an LCD display and laptop.
If it really is a USB<> RS485 adapter, then there is no easy way to adapt/convert it into a USB<> RS488 adapter.
The 4th picture is on a 40pin PIC and MAX488 and that can't be the schematic for the adapter......
So I'm wondering if the problem is in needing to connect the USB 'module' to the 40pin PIC/max488 ?

It'd probably be easy IF we were sitting at his bench.......

Jay
ertansuluagac



Joined: 13 Jul 2017
Posts: 127
Location: IZMIR

View user's profile Send private message Send e-mail

PostPosted: Mon Mar 23, 2020 5:06 am     Reply with quote

USB-TTL converter, I connected max488 to the card. It worked very smoothly. I also can't see an error on my card. But I couldn't run it.
https://www.robitshop.com/urun/usb-ttl-seri-donusturucu-kart-pl2303?gclid=EAIaIQobChMI5ruJi7qw6AIVzRsYCh2i9QMAEAQYAiABEgKQ1fD_BwE
_________________
Es
temtronic



Joined: 01 Jul 2010
Posts: 7349
Location: Greensville,Ontario

View user's profile Send private message

PostPosted: Mon Mar 23, 2020 5:31 am     Reply with quote

Please perform these simple 'loopback' test.

Test #1. Connect a jumper from USBTTL - TX pin to USBTTL - RX pin. Run your PC terminal program, every key pressed on the PC KBD should go to the USB module, out the TX pin, back into the RX pin, through the USB port and onto the PC screen. This will CONFIRM the USB module is working.

Test #2. Remove jumper from #1 test, connect your MAX488 chip. ADD two jumpers, A to X, B to Y. Now, any key pressed should go all the way to the 488 pins, 'loopback' and be displayed on the PC screen. This will CONFIRM the MAX488 is working properly.

Test #3. Connect to your other 'device'. Be sure to setup the PC terminal program for the correct baudrate, bits, etc. to match the other 'device'. You may need to add/delete any bias or termination resistors.

Please post information as to what the 'device' is you're connecting to. A 'link' to the datasheet would really help. It could be something simple. The 'device' might default to 9600 baud but your terminal defaults to 57600. That doesn't work, it might show 'garbage' characters. Changing the 57600 to 9600 should fix it.
Display posts from previous:   
Post new topic   Reply to topic    CCS Forum Index -> General CCS C Discussion All times are GMT - 6 Hours
Goto page Previous  1, 2, 3
Page 3 of 3

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group