Where I discuss various serial monitor applications and why I believe CoolTerm is the best one.

Introduction#

The serial port is an invaluable, if not mandatory tool, for developing programs in embedded computing. Given the popularity of software development for embedded computers, one would think there would be a clear answer or solution. For several years, I wasn’t able to determine the best solution. However, after more work on my part to understand a specific solution, I can conclusively say use this multiplatform, free solution: CoolTerm

Updated: Where I describe the different options for using a serial monitor and the serial software in AVR_C and change my recommended programs.

Introduction#

CoolTerm appears to be malware on some systems and PuTTY, its important to install from the proper site, has better security. PLEASE ENSURE YOU DOWNLOAD IT FROM THIS SITE ONLY: https://freeware.the-meiers.org/

For macOS, I do likeSerial, however, this is a $40 serial program. For free, the solutions is tio, which can be easily installed using Homebrew or CoolTerm.

Where I describe how to use the GNU Linker wrapper capability and variable arguments to enhance printf() for better debugging.

Introduction#

This recent post fascinated me. It describes a feature of the GNU linker called wrapping which allows you to replace an existing symbol (command) with a new version. The example describes adding a timestamp to printf(). While, for me, this might be a solution looking for a problem, I really liked the idea. And at the very least wanted to add the concept to AVR_C.

Introduction#

Where I share various observations as to how to use the Pico with the Arduino software framework and the legacy (~1.8.19) Arduino IDE.

Pico Reset Button#

While most RP2040 boards will have a Reset button, the Pico does not. Why? To save costs. It also has a micro-USB connector instead of a USB C connector for the same reason. The single best way to ensure your Pico uploads properly (or more accurately) the Arduino IDE uploads to the Pico, properly is to press and hold the Boot/Sel button then unplug and plug-in the Pico. This can be required a great deal when testing I2C and the unplug/plug-in is a bit of a pain.

Where I explore how to use the Pico’s abundance of I2C interfaces to create 2 separate I2C instances.

Sources#

• GitHub Repository

Introduction#

I have been using the Arduino framework and legacy IDE (1.8.19, not the 2.0 version) to develop code on the Raspberry Pi Pico. The Pico is an incredible board, well worth using due to its outstanding price/performance ratio. For only $4, you can buy a very powerful, very well documented and easily available microcontroller. With the addition of the Arduino framework, it makes using the Pico a simple decision for a lot of Uno projects..

Where I demonstrate how to use a GitHub repository to develop a data logger with the Arduino Uno to measure and record analog values. In this example, I will be measuring voltage, however the same approach could be used to measure capacitance, temperature, or light etc.

NOTE: The SparkFun Qwiic Alphanumeric Display uses 3.3V and not the 5V from the UNO! Please use a level-shifter or a Pi Pico (or equivalent) when using this specific display.#

SparkFun Qwiic Alphanumeric Display

Where I describe how to improve the performance of your programs by accessing the input/output (I/O) ports on the Arduino Uno, natively.

Introduction#

The Arduino framework and Uno hardware has performed an admirable job in abstracting much of the complexity of the ATmega328P into something which is easier to understand. This approach works well for a beginner in microcontrollers and embedded C programming. Once you begin to understand how the ATmega328P works, its not unusual to find the Arduino simplification is holding you back.

Where I demonstrate different methods of measuring a servo pulse to ensure it meets requirements.

Introduction#

In the entry on servos I discussed the specific pulse requirements to make a servo move. In a nutshell, a servo needs a positive pulse .5ms to 2.3ms in a 60Hz signal. Or to put it another way, it requires a 60Hz signal with a duty cycle ranging from 3% to ~14%.

Reference page for Bloom configuration and commonly used avr-gdb commands.

Sources#

• gdb Resources
• Online User Manual: Debugging with GDB
• Bloom (replaces avarice)
• Microchip SNAP (replaces the Atmel Dragon)
• Atmel-ICE Debugger more expensive version for both ARM and AVR

Bloom Configuration#

Atmel ICE Debugger Configuration#

environments:
  default:
    debugTool:
      name: "atmel-ice"

    target:
      name: "atmega328p"
      physicalInterface: "debug-wire"
      disableDebugWirePreDisconnect: false
      manageDwenFuseBit: true
      variantName: "atmega328p-pu"

    debugServer:
      name: "avr-gdb-rsp"
      ipAddress: "127.0.0.1"
      port: 1442

insight:
  enabled: true

avr-gdb Configuration#

.gdbinit#

set history save on
set history size 10000
set history filename ~/.gdb_history

file main.elf
target remote :1442
set listsize 0

define cll
make 
load main.elf
mon reset
refresh
list
end

Where I describe how to use the servos() interface in AVR C.

Sources#

• Analog Feedback Micro Servo - Product ID: 1449 Servo to be used in entry.
• Analog Feedback Servos
• Arduino Lesson 14. Servo Motors
• Adafruit Servo Motors

Introduction#

Servos are a powerful addition to the embedded programming toolkit as they enable motion. Not high-speed motion as in a electric motor, however, motion which can be easily controlled and typically in an arc or as angles. Servos are much more precise as to how they can move in comparison to electric motors. See Sources above for a few example tutorials as to how to use them.