-2
\$\begingroup\$

This question already has an answer here:

I have the following module which can be found on this website :- http://www.elecrow.com/uart-ttl-to-rs485-twoway-converter-p-1545.html

It is simply a bidirectional Uart TTL to RS485 converter. I have included the images below. The 8 pin small ic (U1) is RS485 which is itself unidirectional. I need help in identifying the second chip (U2), the one with 14 pins. This ic is responsible for switching between transmission and reception mode of the 485 ic. I have the module with me but the name of the ic has been erased. Plus there is no datasheet for the module available on the website. Could anyone please suggest what is the name of this ic??

enter image description here

enter image description here

\$\endgroup\$

marked as duplicate by Bence Kaulics, Daniel Grillo, DoxyLover, Sparky256, Leon Heller Jul 30 '16 at 17:24

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • \$\begingroup\$ I guess, it's a cheap MCU or FPGA. It has to detect TX and enable transmit of U1. After the send is complete it has tu switch to receive. Kind of autobaudrate detector and timer. \$\endgroup\$ – Marko Buršič Jul 30 '16 at 6:54
  • 1
    \$\begingroup\$ Take some fuming nitric acid, decap the 14 pin device, and stick the die under a microscope. Anything else is going to be guesswork. \$\endgroup\$ – Connor Wolf Jul 30 '16 at 7:16
  • \$\begingroup\$ The bastards removed the Chip id. \$\endgroup\$ – Alex Jul 30 '16 at 7:53
  • \$\begingroup\$ Why do you want to know? \$\endgroup\$ – Bruce Abbott Jul 30 '16 at 12:33
0
\$\begingroup\$

Added bottom layer

Added bottom layer

Surely it must drive DE/RE pin (SOIC8 2 and 3) of transceiver depending from TXD (if TXD is LOW then DE/RE HIGH).

\$\endgroup\$

Not the answer you're looking for? Browse other questions tagged or ask your own question.