Table of Contents

TM7705 A/D module

tm7705.jpg

This TM7705 A/D module is manufactured in China and sold as an AD7705 acquisition board with two 16-bit input channels. A 2.5V voltage reference is also on the board.

The TM7705 mimics the operation of the AD7705 and the TM7705 data-sheet, which is only available in Chinese, is similar to the AD7705 original.

Pinout

Module

A1+ o                 VCC   o o  GND
A1- o                 CS    o o  RST
A2+ o                 DIN   o o  SCK
A2- o                 DRDY  o o  DOUT
          TM7705 I.C.
          
RST     HAS  10K PULL UP
A1-/A2- HAVE 0R  PULL DOWN

DIN  = MOSI
DOUT = MISO

Raspberry Pi

The module can easily be connected to the RPi using the following pins.

         +---P1---+
         //      //
3V3      17      18 
MOSI     19      20 GND
MISO     21      22 
SCLK     23      24 CE0
GND      25      26 CE1
         +--------+
         
SCLK = SERIAL CLOCK
CE   = CHIP ENABLE / SELECT

TM7705

As expected the pinout is the same as the AD7705.

       SCLK     o    o GND
       MCLK IN  o    o VDD
       MCLK OUT o    o DIN
       !CS      o    o DOUT
       !RESET   o    o !DRDY
       AIN2+    o    o AIN2-
       AIN1+    o    o REF IN-
       AIN1-    o    o REF IN+

Resources

AD7705 data-sheet
Titanmec TM7705