Tag Archives: module

Pi/104 – Pi Compute carrier board

Pi/104 is a Pi Compute carrier board in PC/104 format with industrial durability.

The Pi Compute Module is a powerful tool for custom electronics projects. But if your project requires industrial grade specifications, you’re currently out-of-luck. This is where Pi/104 comes in – with a wide temperature rating and a power supply that encompasses common industrial cabinet voltages. Pi/104 doesn’t try to do too much out of the box. Instead, it relies on an industry standard form factor for accessories, which allows people to build custom stacks to meet their goals in a cost effective way. It also means the base board is cheaper, bringing an industry-ready board to the hobby market.

Features

  • Based on the PC/104 format, compact, sturdy, and stackable.
  • Uses the “OneBank” connector leaving more PCB area and cheaper than a full PCIe/104 connector.
  • “OneBank” has 5/3.3 V and two USB channels allowing you to use USB-powered peripherals in the stack such as cellular modems, Wi-Fi cards, USB to SATA, FPGA, and serial connectors. (Note: PCIe pins in OneBank connector are not used.)
  • Flexible power. Board can be powered through the wire terminals (8 to 35 volts), OneBank connector (5 V and 3.3 V), or through the USB OTG connector.
  • USB OTG connector supports full range of functionality including OTG and USB boot.
  • Display flexibility with either HDMI or DSI support as well as a camera through the CSI port
  • IDE-style connectors for GPIO, making I/O ribbon cables easy to find. Connector closest to module is pin compatible with Raspberry Pi and has been successfully tested with several HATs. The other connector carries the rest of the compute module pins and some extra grounds.
  • Recessed Ethernet connector allows for a full size, standard ethernet cable to be used even in stack configuration.
  • On-board microSD card slot allows for use of Pi Compute 3 Lite modules.

Specifications

  • 2 x USB A
  • 1 x microUSB OTG
  • 1 x HDMI
  • 1 x 10/100 Ethernet
  • 1 x microSD slot (CM3L only)
  • 1 x CSI
  • 1 x DSI
  • 59 x GPIO in two IDE-style connectors
  • OneBank stacakble connector with 2 USB and 5/3.3 V
  • Wide power supply, 8-36 V
  • Temperature spec with Pi Compute Module, -25° C to 85° C
  • Temperature spec without Pi Compute Module, -40° C to 85° C

LC-04 4 Channel Logic Converter 3.3V – 5.0V

If you have ever tried to connect a 3.3V device to a 5V system, you know what a challenge it can be. The LC-04 bi-directional logic level converter is a small device that safely steps down 5V signal to 3.3V and steps up 3.3V to 5V at the same time. In this instructable, mybotic explained the procedure to use the LC-04 bi-directional logic converter.

Description:

The LC-04 module offers bi-directional shifting of logic level for up to four channels. The logic level HIGH (logic 1) on each side of the board is achieved by 10K Ω pull-up resistors connected to the respective power supply. This provides a quick enough rise time of logic level to convert high frequency (400KHz I²C, SPI, UART etc.) signals without delay.

This module has the following features:

  • Dual-supply bus translation :
    • Lower-voltage (LV) supply can be 1.5 V to 7 V
    • Higher-voltage (HV) supply can be LV to 18 V
  • Four bi-directional channels
  • Small size: 0.4″ × 0.5″ × 0.08″ (13 mm × 10 mm × 2 mm)
  • Breadboard-compatible pin spacing

    The bi-directional level-shifting circuit
    The bi-directional level shifting circuit

The Pinout:

The LC-04 logic level converter has two types of pins:

  1. Voltage input pins :
    • 2 pins (GND and LV) on Low Voltage  side
    • 2 pins (GND and HV) on High Voltage  side
  2. Data channels :
    • 4 pins (LV1, LV2, LV3, and LV4) on Low Voltage  side
    • 4 pins (HV1, HV2, HV3, and HV4) on High Voltage  side

Pin HV and LV set HIGH (logic 1) logic level on High voltage side and Low voltage side respectively, with respect to the GND.

Data channel pins shift logic levels from one voltage reference to another. A low voltage signal sent into LV1, for example, will be shifted up to the higher voltage and sent out through HV1. Similarly, a high voltage signal sent into HV1 will be shifted down to the lower voltage and sent out through LV1.

LC-04 Bi-directional logic level converter pinout
LC-04 Bi-directional logic level converter pinout

Parts List:

  1.  LC-04 4 Channel Logic Level Converter
  2. Arduino Uno Board and USB Cable
  3. Breadboard
  4. Crocodile Clip (optional)
  5. Multimeter

The Wiring:

The wiring is pretty simple. You may even omit the breadboard by making end-to-end connections. Two types of connections are required:

  1. Pin connection to shift down (5V to 3.3V)
  2. Pin connection to shift up (3.3V to 5V)
Pin Connection to Shift Down:
  1. LV to 3.3V
  2. LV’s GND to multimeter’s black probe
  3. LV3 to multimeter’s red probe
  4. HV to 5V
  5. GND to UNO’s GND
  6. HV3 to Digital Pin 4
Logic level shift down using LC-04 logic level converter
Logic level shifting down using LC-04 logic level converter
Pin Connection to Shift Up:
  1. LV to 3.3V
  2. LV’s GND to UNO’s GND
  3. LV3 to Digital Pin 4
  4. HV to 5V
  5. GND to multimeter’s black probe
  6. HV3 to multimeter’s red probe
Logic level shifting up using LC-04 logic level converter
Logic level shifting up using LC-04 logic level converter

Using OV7670 Camera Sensor With Arduino

Developing a hardware project became much easier thanks to the growing number of the various sensors and actuators modules, which give you the ability to shift your ideas into a wider range of applications. This tutorial presents the steps of how to use OV7670 Camera Sensor Module STM32 with Arduino.

To follow the tutorial, you will need these parts:

  1. Arduino Uno Board and USB
  2. OV7670 Arduino Camera Sensor Module STM32
  3. Resistor (2x10K & 2×4.7K)
  4. Breadboard

The OV7670 image sensor is a small size, low voltage, single-chip VGA camera and CMOS image processor for all functions. It provides full-frame, sub-sampled or windowed 8-bit images in various formats, controlled through the Serial Camera Control Bus (SCCB) interface.

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The camera module is powered from a single +3.3V power supply, and external clock source for camera module XCLK pin. The OV7670 camera module built-in onboard LDO regulator only requires single 3.3V power and can be used in Arduino, STM32, Chipkit, ARM, DSP, FPGA and etc.

This is pin definition table of the module:

OV7670 Pin Definition
OV7670 Pin Definition

OV7670 module specification:

  • Optical size 1/6 inch
  • Resolution 640×480 VGA
  • Onboard regulator, only single 3.3V supply needed
  • Mounted with high quality F1.8 / 6mm lens
  • High sensitivity for low-light operation
  • VarioPixel® method for sub-sampling
  • Automatic image control functions including: Automatic
  • Exposure Control (AEC), Automatic Gain Control (AGC), Automatic White Balance (AWB), Automatic
  • Band Filter (ABF), and Automatic Black-Level Calibration (ABLC)
  • Image quality controls including color saturation, hue, gamma, sharpness (edge enhancement), and anti-blooming
  • ISP includes noise reduction and defect correction
  • Supports LED and flash strobe mode
  • Supports scaling
  • Lens shading correction
  • Flicker (50/60 Hz) auto detection
  • Saturation level auto adjust (UV adjust)
  • Edge enhancement level auto adjust
  • De-noise level auto adjust

The connection between the module and the Arduino uses 6 analog pins and 8 digital pins, and they have to be connected as shown in this figure:

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The software requirements are the Arduino IDE and Java Development Kit (JDK). To run the project, you have to execute a java code through the command line. The script will search for images received from Arduino and then saves them on the PC.

Source code, additional needed files, and setting up instructions are all available at the tutorial page.

A $20 Heart Rate Module For Health-Tech Projects

Heart rate monitoring is a common procedure for most of health related projects. Therefore, producing sensors modules and circuit boards for such tasks will facilitate and push forward the development of new health-tech projects.

Maxim Integrated, an analog and mixed-signal integrated circuits manufacturer, has developed a new module for measuring heart rate and pulse oximetry. It’s called “MAXREFDES117#”, derived from Maxim Reference Design, and it is a small board which is compatible with Arduino and Mbed boards, enabling a wide range of possibilities for developers.

MAXREFDES117# Board
MAXREFDES117# Board

MAXREFDES117# can be powered by 2 to 5.5 volts. It is a photoplethysmography (PPG)-based system that uses optical method for detecting heart rate and SpO2. It consists of three main parts:

1. MAX30102, a high sensitivity heart rate and pulse oximetry sensor. It is used with integrated red and IR LEDs for heart rate and pulse oximetry monitoring.

2. MAX1921, a low-power step-down digital-to-digital converter. It generates 1.8 V from input to supply the sensor.

3. MAX14595, a high speed logic-level translator. It works as an interface between the sensor and the connected developing board.

MAXREFDES117 Block Diagram
MAXREFDES117 Block Diagram

The board size is only 0.5” x 0.5” (12.7mm x 12.7mm) and has low power consumption that make it suitable for wearable applications. Thus, it can be placed on a finger, an earlobe, or other fleshy extremity.

MAXREFDES117# uses open-source heart-rate and SpO2 algorithm in its firmware. It also can be used with any controller having I2C interface. But the available firmware had been tested only on 6 different development boards, three of them are Arduinos (Adafruit Flora, Lilypad USB, and Arduino UNO), and the others are mbed boards (Maxim Integrated MAX32600MBED#, Freescale FRDM-K64F, and Freescale FRDM-KL25Z).

The MAXREFDES117# Firmware Flowchart
The MAXREFDES117# Firmware Flowchart

Accuracy of data collected by MAXREFDES117# depends on the used platform. According to the results with tested boards, Arduino boards give less accuracy than mbed ones because of theirs smaller SRAM size.

MAXREFDES117# is available for $20, it can be ordered online through the website.
More detailed information and quick start guide are presented here. In addition, all of the source files including schematic, PCB, BOM, and firmware are open and can be reached at the official product page.

Reverse engineering a server CPU voltage regulator module

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Andy Brown wrote a detailed article on reverse engineering a CPU voltage regulator:

A recent ebay fishing expedition yielded an interesting little part for the very reasonable sum of about five pounds. It’s a voltage regulator module from a Dell PowerEdge 6650 Xeon server.
I originally bought this because I had the idea of salvaging parts from it to use in another project. These are high quality modules that will have very good inductors and sometimes an array of high value ceramic capacitors that could be re-used (ceramics of at least 22µF at 16V and above are rather pricey at the moment). So the VRM arrived and I was rather impressed with the build quality and decided to have a go at reverse engineering it.

Reverse engineering a server CPU voltage regulator module – [Link]

RTL8710 Is a New ESP8266 Competitor

RTL8710

In the last two years, ESP8266 was the Wifi Chip/Module which dominated the market of hobbyists, even a lot of commercial products use ESP8266, due to the low price, ease of use and large community around ESP8266.

RTL8710 is a Wifi network solution from the Taiwanese Company Realtek. It can operate independently, or as a slave to another MCU host. The same way of ESP8266.
RTL8710 has a built-in ARM Cortex M3 MCU at 166 MHz, 1MB flash and peripherals like UART, PWM, I2C, GPIO and PCM, a more detailed comparison is shown in the  table bellow:

Table courtesy of cnx-software
Table courtesy of cnx-software

If you like to have a quick hands on RTL8710, then you can order a development board for RTL8710.

RTL8710DK

Via: cnx-software

HC-12 433MHz wireless serial communication module configuration

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HC-12 are cheap 433MHz wireless serial port communication modules with a range up to 1800m in open space. Each costs about $5 when bought from China, and 2 of them can create wireless UART link that can be used, for example, to transfer telemetry data from UAV. Or drive IoT device. Or connect sensors. Or whatever else one can think of.

HC-12 433MHz wireless serial communication module configuration – [Link]

Raspberry Pi Wifi module without USB

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This board will let you add WiFi functionality to your Raspberry Pi Zero without having to sacrifice the only available high speed USB port. The board is based on ESP8266 Wifi module.

WiFi on a Raspberry Pi using the HAT connector and an ESP8266. The goal of this project is to add WiFi to the Raspberry Pi Zero while keeping the USB port free for devices or OTG connection to another host.

Raspberry Pi Wifi module without USB – [Link]

1.3V – 15.5V @ 2 Amps Power Supply

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Here is a low cost and easy to build power supply based on a some Chinese DC-DC converter modules:

This is a small size power supply with low cost and easy to make that only taking about 5 more hours. I was very happy with it and would share with you.

Power Supply Specifications

Input: 5v-16v/3A DC

Output: 1.3V – 15.5V/2 Amps

1.3V – 15.5V @ 2 Amps Power Supply – [Link]

Connecting HC-05 Bluetooth Module to Arduino

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TechDepot Egypt @ instructables.com has published a tutorial on how to connect a HC-05 Bluetooth module to Arduino. Turorial shows how to connect the module with Arduino and example code is included.

It is worth noting that the HC-05 power in (Vcc) uses 5V, while the transmit and receive (TXD and RXD) logic signal uses 3.3V. Accordingly sending signals from the HC-05 module to Arduino is ok as the Arduino I/O pins can safely receive up to 5V but the issue is when Arduino tries to send the data to the HC-05 with signal level 5V, in this case it is required to use a voltage divider as we will see during the tutorial.

Connecting HC-05 Bluetooth Module to Arduino – [Link]