OBJEX Link v1.7-C3 RISCV

Overview

OBJEX Link v1.7-C3 is the RISC-V version of the series. This version of OBJEX Link v1.7-C3 is based on the new ESP32-C3 which has a 32-bit single-core RISC-V processor. It's very useful for various IoT devices (wearables for example) and for applications that require higher power efficiency or other features such as Bluetooth 5.0, and WiFi 4.
IoT Applications: Wearable devices, Smart Home & Cities, IIOT, Predictive Maintenance, Agriculture Automation.
It's also ideal for rapid prototyping, advanced research projects, and robotics projects.

Key features

  • Compact size 24x24mm, high component density
  • Modular design for a wide range of applications
  • Designed to ensure easy reuse
  • Low power consumption (deep sleep: 12uA)
  • Based on ESP32-C3 RISCV
  • WiFi 4 & BLE 5.0 connectivity
  • 22 programmable GPIOs
  • USB-C Type 2.0
  • Tiny battery connector
  • Compatible with Arduino and MicroPython
  • Battery manager(fast-charge)
  • Support for external PSRAM

Block diagram

Block diagram - OBJEX Link v1.7-C3

Pinout

The picture below shows the OBJEX Link v1.7-C3 pinout of its two M0 slots. As you can see some pins like SDA and SCL are present on both M0 slots in order to use at best all pins in the two slots.
For more information on individual GPIOs, we recommend reading the datasheet of the microcontroller used by OBJEX Link v1.7-C3.

Protoboard v2.0

The protoboard v2.0 can be used with OBJEX Link v1.7-C3, but the number/name of Pin/GPIOs in some cases does not match with the silkscreen.
OBJEX Link v1.7-C3
Protoboard v2.0
5V
5V
3V3
3V3
BATT
BATT
VDD
VDD
not used
EN
RTS
RTS
Battery lvl(GPIO3 - ADC1_CH3)
GPIO14
GPIO20
SDA
GPIO21
SCL
GPIO2
D25
GPIO4
D16
GPIO5
D5
GPIO6
D39
GPIO7
D13
GPIO10
D18

Schematic

OBJEX_LINK-Rev1.7_RISCV.pdf
536KB
PDF
IO_SlimStack_rev1.7-C3.pdf
76KB
PDF

Power Consumption

All tests concerning the consumption and energy performance of the board have been carried out using the following tools: Power Profiler Kit II and RIGOL DS1054Z.
Board status
Average
Max
Unit
Idle
18.08
30.05
mA
WiFi On
TBC
TBC
mA
Bluetooth On
TBC
TBC
mA
Deep Sleep
12.14
14.21
uA

Technical specifications

Microcontroller
ESP32-C3FH4
I/O
ADC, SPI, PWM, UART, I2C, I2S
Modules type
x2 M0 or x1 M1
USB
USB-C Type 2.0
WiFi
WiFi 4 | IEEE 802.11 b/g/n-compliant
Bluetooth
Bluetooth® 5.0
LDO
Vin = 5V / Vout = 3.3V
Battery manager
1A Maximum
Battery type
LiPo / Li-Ion
Operating temperature range
−40°C to 105°C
Dimensions
24mm x 24mm
PCB Thickness
1.6mm
Thickness(PCB with USB-C)
5mm
Weight
3.24g

Warranty & Certifications

OBJEX Link v1.7-C3 is currently an experimental prototype, but all components used are RoHS compliant.
OBJEX Link v1.7-C3 does not yet have all the certifications needed for mass sale. Currently, only a few prototypes are distributed for testing and research purposes, and not for real use on IoT devices.