Logo   LOGGER Processor Module

Published Source License
Screen Shots
SD Card Issues
Updating Firmware

Reference Information
Airflow Setup
Development Environment
I2C Addresses
Module Switches Setup
Processor Module Pinning
WattNode Modbus Adapter

Development History
Project Status
Software Revisions

PJRC hardware
ESP8266 Information

Processor Module Pinning

In this table the pinning listed in the PJRC Teensy, PJRC SD small and Wireless Sensors colums supports a number of development boards. These columns are not important for the Logger Developers Kit.

NOTE: pins on the large PJRC USB module are listed in the table as Teensy The pin numbers indicated are the "Digital Pins" printed on the Teensy card in grey. (These do not count around the card the way a DIP does.)

Function ESP pin Cat-5 SD adapter PJRC
Wireless Sensors
Enable I/O Devices (turns on voltage regulators)   1 White/Orange       Reset,
Power for Sensirion (SHT10 pin 5)
SCL (ESP pullup expected) GPIO2 on ESP8266
GPIO22 on ESP32
2 Orange       SCL for Sensirion (SHT10 pin 6),
Power for Onewire Temperature

Data Ready
GPIO5 3 White/Green        
OneWire Data GPIO0 4 Blue       SDA for Sensirion (SHT10 pin 1),
Data for Onewire Temperature
GND GND 5 White/Blue 3, 6 GND (also AGND?)   GND (SHT10 pin 2)
spare   6 Green        
+5V to Voltage Regulator then to 3.3V 7 White/Brown pin 4 does not connect to the Cat-5, it gets locally regulated 3.3V      
SDA (pullup required) GPIO4 on ESP8266
GPIO21 on ESP32
8 Brown        
SS (not chip select) GPIO17 on ESP32 (GPIO10 is missing on SparkFun Thing)
GPIO10 on ESP8266 (pin 16 was used on older modules used for reset)
  1 Teensy 4    
MOSI GPIO13   2 Teensy 11    
SCK GPIO14   5 Teensy 13    
MISO GPIO12   7 Teensy 12    
Analog Input A          


SD Card

Soldering wires to pins 1 thru 7 of an SD card adaptor works without modification.

The first line is the end of the adapter with the notch. Pin 9 at this end is displaced from the edge. Yes the numbering is not in order.

Pin #Function
1SS (not chip select)
4VCC (+3.3V)

Secure Digital Pinout
Pin # Pin name SD Signal Function SD Mode SPI Signal Function SPI Mode
1 DAT3/CS Data Line 3 Chip Select/Slave Select [SS]
2 CMD/DI Command Line Master Out/Slave In [MOSI]
3 VSS1 Ground Ground
4 Vdd Voltage Supply [2.7v or 3.6v] Voltage Supply [2.7v or 3.6v]
5 Clock Clock Clock [SCK]
6 Vss2 Ground Ground
7 DAT0/D0 Data Line 0 Master In Slave Out [MISO]
8 DAT1/IRQ Data Line 1 Unused or IRQ
9 DAT2/NC Data Line 2 Unused

Cables and Parts

Adafruit Selectable programming Module (Recommended programmer can be selected for 3.3V or 5V operation)
Adafruit Serial programming cable

Breakout Boards

1230 module
Other Breakouts

Large PJRC SD Adaptor

The PJRC Rev1 SD adaptor works without modification. The Rev2 SD adapter adds pullup resistors which are in conflict with the processor pin usage and must be removed if the Rev2 adaptor is used.

Small PJRC SD Adaptor

The Small PJRC SD Adaptor works without modification. The jumper for 3.3 Volt operation must be installed. The 5 Volt pin then becomes the 3.3 Volt input. The SS pin on this module interferes with normal boot of an ESP8266 when it is connected to pin 15. The SD card chip select has been moved to pin 16 to avoid this issue.

Modules Available

Sparkfun FTDI equivalent

While the Raspberry Pi module is cheaper it does not do the FTDI thing, and anything but an authentic FTDI chipset is a recipe for great pain according to the ESP8266 blog. Sparkfun FTDI equivalent

Newer parts ESP-12F are available

Interfacing a LOGGER to a Wattnode Modbus meter

To connect a LOGGER to a WattNode Modbus meter an external modbus transceiver interface is necessary. The first table below shows how to connect a LOGGER Cat-5 connector to a MAX3485 RS485 to Modbus transceiver. The second table shows how to connect the transceiver to the 4 pin Com port of the Wattnode Modbus meter.

Cat-5 to MAX3485
Purpose Cat-5 name Cat-5 pin and color MAX3485 name MAX3485 pin
Enables output to Modbus PE (Peripheral enable) 1 White/Orange ~RE (not receiver enable> 2 (also goes to 3)
  PE (Peripheral enable) 1 White/Orange DE (driver output enable> 3 (also goes to 2)
Serial data out (from GPIO2) SCL/SLK 2 Orange RO (Receiver output to ESP) 1
Ground GND 5 White/Blue GND 5
Power (4 to 4.5V nominal) Vbus 7 White/Brown Vcc 8
Serial data in (GPIO4) SDA 8 Brown DI (serial data from ESP) 4

MAX3485 to WattNode Modbus meter
MAX3485 name MAX3485 pin Wattnode Pin
B inverting receiver input 7 A-
A noninverting receiver input 6 B+
Ground 5 C
Note: In spite of the naming this will not work if A and B are reversed.

AllSensors E1NS package to Cat-5
AllSensors Name AllSensors pin Cat-5 Pin
Gnd 1 5
Vs 2 1 (+3.3 if insufficent current)
SDA 3 8
SCL 4 2

Sparcfun Qwiic to Cat-5
Sparcfun Name Sparcfun pin Cat-5 Pin
Gnd (black) 1 5 white/blue
Vs (red) 2 6 green (this spare pin must be tied to +3.3 at P1 or P2 on processor board)
SDA (blue) 3 8 brown
SCL (yellow) 4 2 orange

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