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NEW Arduino Uno R4 Boards - Minima & WiFi

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(@dronebot-workshop)
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Two new Arduino Uno boards - the Minima and WiFi. Let's examine them and test some of their unique features, including the CAN Bus and LED Matrix.

The Arduino Uno R3 was released in 2011. It has become the most popular maker and experimenter microcontroller board today, thanks to its ease of use and open-source design that allowed several low-cost “clones” to be made available.

Now, after a dozen years, Arduino has updated the Uno. Actually, they did make a WiFi Uno in 2018, but nobody noticed, and there was a “mini” collectors edition Uno in 2021. But this update is so big they made it into two boards!

Arduino has released the low-cost (20.00 USD) Uno R4 Minima and the full-featured Uno R4 WiFi boards (27.50 USD). These boards are pin-for-pin compatible with the older Uno R3 and are also 5-volt logic devices, rare these days. This means compatibility with your existing shields and prototyping boards.

The new boards are powered by the Renesas RA4M1 microcontroller, running at 48 MHz. This provides an emulation of the ATMega328P used in the original board and also adds new features, several that we will test out today.

Among the new features we will try out are the following:

12-bit DAC - We'll generate a sine wave with a library that makes it very easy.
CAN Bus connection - We'll connect 2 Minima boards using a CAN Bus.
WiFi Access Point - We'll build an Access Point with a web page to control an LED.
LED Matrix Display - We'll use the online Matrix Editor to create patterns.

We’ll also run benchmark tests on these boards and compare them to the older Uno R3, as well as a few other popular microcontroller boards.

Here is the Table of Contents of today's video:

00:00 - Introduction
01:41 - Arduino Uno R4 Boards
13:10 - Boot & 8mA Current Limitation
15:27 - Arduino R4 IDE Setup
16:40 - DAC & Sine Wave Hookup
18:21 - DAC - Sine Wave Code
20:28 - DAC - Sine Wave Demo with scope
21:37 - CAN Bus Explainer & Hookup
30:50 - CAN BUS Code - canwrite
32:28 - CAN BUS Code - canread
33:29 - CAN BUS Demo - 2 Minimas
35:11 - Uno R4 WiFi & ESP32
38:19 - WiFi Access Point Code
42:19 - WiFi Access Point Demo
43:19 - LED Matrix Explainer
46:18 - LED Live Preview Code
47:52 - LED Live Preview Online Edit & Demo
49:44 - Benchmarking Setup & Code
52:19 - Benchmark Test Results
54:56 - Conclusion

These are two unique boards, certain to interest experimenters and educators (the LED matrix opens up a lot of interesting classroom displays).

Hope you enjoy the video!

Bill

"Never trust a computer you can’t throw out a window." — Steve Wozniak


   
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Ron
 Ron
(@zander)
Father of a miniature Wookie
Joined: 3 years ago
Posts: 6546
 

I had not noticed the low pin current, that's a little concerning.

First computer 1959. Retired from my own computer company 2004.
Hardware - Expert in 1401, and 360, fairly knowledge in PC plus numerous MPU's and MCU's
Major Languages - Machine language, 360 Macro Assembler, Intel Assembler, PL/I and PL1, Pascal, Basic, C plus numerous job control and scripting languages.
Sure you can learn to be a programmer, it will take the same amount of time for me to learn to be a Doctor.


   
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(@dronebot-workshop)
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@zander Yes indeed!  The biggest concern, at least to me, is that someone might unknowingly plug in a shield that has a few status LEDs with 220-ohm or lower resistors. Next, they wonder why their Arduino is fried!

In all fairness though, the Raspberry Pi Pico has a maximum of 50mA for all pins combined, so if you were to hook up a bunch of LEDs to it, you could also damage it.

The ESP32, on the other hand, is rated at up to 40mA per pin, but they recommend not exceeding 20mA due to power supply concerns (when you power an ESP32 using 5-volts you are using the internal regulators to make it 3.3-volts). 

Arduino does mention the 8mA limit several times in their documentation, but I think they should go further and put a red warning sticker or something on the board, so you're aware of it when you buy it.

😎

Bill

"Never trust a computer you can’t throw out a window." — Steve Wozniak


   
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rommudoh
(@rommudoh)
Member
Joined: 11 months ago
Posts: 32
 

A nice change is that now it is using a buck converter instead of a LDO for converting the Vin/Barrel voltage. This is more efficient and produces less heat. I used an external buck converter for my Dalek robot project because of that. With a board like this, I'd feel safer to directly use Vin.

Also, yay for USB-C!

Current projects:
- Modding my Gameboy Advance SP
- Turning Dalek into robot
Finished projects:
- Talking plant monitor (ESP8266)
- Mail box monitor (ESP8266-01S)
Other devices:
- Raspberry Pi 4B 4GB running Home Assistant


   
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(@jackpo)
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Posts: 1
 

@rommudoh


   
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(@dronebot-workshop)
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Posts: 1043
Topic starter  

@rommudoh That seems to be the way they are going with their new boards, the Nano ESP32 also uses a buck converter.

😎

Bill

"Never trust a computer you can’t throw out a window." — Steve Wozniak


   
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