Embedded   




 Today's Daily Deal from Apress 9/25/2017


Building Embedded Systems 

9.99 USD 39.99 USD 
9.99 EUR 35.69 EUR 

Also available in GBP and CHF* 


Get this deal

    Posted by Changyi at 11:55 AM 0 Comments  

 GIT Submodule 8/04/2017

Unlike SVN, GIT does not have the concept of external property. The closest it has is something called submodules. And here is the steps I took to create submodules:

*) Clone the repository

*) under local copy, create a folder called "submodules"

*) put any file, such as abc.txt under submodules

*) add abc.txt to the repository, and commit it. GIT does not support empty folders. This file will be used to circumvent this rule before we add links to the real submodules

*) open a cygwin windows, enter the submodules folder we created early

*) type in git submodule add URL, where the URL is the path to the submodule repository

*) Use tortoiseGit to switch the submodule to the tag or branch we want

*) delete abc.txt from the repository

*) commit

To check out, do the following:

*) clone the top repository
  git clone URL_to_top_repository

*) At this point, all submodule links are empty, and they need to be updated:

git submodule update --init --recursive

And after you've been working on the repository, you might need to point your submodules to some new tags. This can be done as following:

git submodule update --remote --recursive

And then go to the specific submodule, use tortoiseGit to switch to the right tag.

    Posted by Changyi at 11:54 PM 0 Comments  

 How to Build a Lego Monster Truck 7/13/2017


The PulseRain M10 board is capable of a lot of things. One of them is to build a Lego Monster Truck, with PWM and Wifi Shields from Sparkfun, plus two DC motors. And here is how:

1) Get the PulseRain M10 board
https://hackaday.io/project/20493-play-fpga-like-arduino

2) Get the Sparkfun Ardumoto shield
https://www.sparkfun.com/products/9815

This shield along does not have the Arduino stackable header and screw terminals (3.5mm pitch). To make the procurement job easy, you could get the Ardumoto Shield Kit instead
https://www.sparkfun.com/products/13201

Update on 10/11/2017: Sparkfun just came out with a new Ardumoto shield (DEV-14129) to replace the old one used in this project (DEV-09815). The difference between those two versions are:

   a) The pin assignments are different. The new one uses pin 2 and pin 4 to control the rotation direction, while the old one uses pin 12 and 13

   b) The new one added some LEDs with 1K ohm resistors on the IO pins directly to show signal activity. However, this will cause problems for the M10 board. Because the M10 board supports dual voltage IO (3.3V/5V), so the IO output for M10 boards are OD (open drain) instead of totem pole. And the 1K ohm resistor on the new shield will pull the voltage below its threshold. So to use the new shield for this project, those 1K ohm resistors have to be removed.

3) Get the Sparkfun ESP8266 Shield
https://www.sparkfun.com/products/13287
solder the connector pin head

The PWM shield needs a 5V input, that can be provided by wiring the 5V pin on ESP8266 shield to the power connector of PWM shield, and stack them together, like the following:



4) Get Two DC 3V-6V Dual Axis Gear Motor from banggood.com. Or they might cost less than $1 each if you buy them from AliExpress

solder wires to the DC motor with 22AWG solid core

5) build the steering mechanism:






6) Hack one of the DC motors according to instructions here, and attach it to the Lego Gear Box

7) Mount the steering mechanism and the DC motor to a Lego 8 x 16 plate using cable tie



8) Attach the other DC motor with two wheels. The wheels are 65 mm in diameter and 28 mm wide. You can get them from Amazon  or banggood.com

9) Attach the DC motors (with wheels) to 3 2 x 16 Lego Plate stack


10) put everything above together with cable tie, connect the DC motor to PWM shield

Now you get yourself a Lego Monster Truck. And stay tuned for firmware/software!

    Posted by Changyi at 11:46 PM 0 Comments  

 HackadayPrize2017 3/22/2017

PulseRain M10 board has officially entered the race for HackadayPrize2017! as "Play FPGA with Arduino"

The project page is

https://hackaday.io/project/20493-play-fpga-like-arduino

And for readers of this blog, please do me a favor by clicking the "Like Project" button on this page. (If you have a GitHub or Twitter account, you can sign in directly.). To tell you the truth, every like this project receives will translate into $1.00 seed money with $200 ceiling. Wow, that can buy hundreds of cups of mid-night coffee!

    Posted by Changyi at 9:38 PM 0 Comments  

 PulseRain M10: A FPGA Board like No Other 3/04/2017

People start asking me why this blog had a long hiatus. And here is what's happening

My coworkers and I have spent the better part of the past 5 months developing and fine-tuning PulseRain's latest product: The M10 FPGA board.

We chose to make the M10 board because we need a platform to verify our FP51-1T MCU core. The FP51-1T is an 8051 core that has single clock instruction cycle. It has 4 stage pipeline structure that can reach above 100MHz on Altera Max10 C8 speed grade device. A lot of open source 8051 core claim to be 1T instruction cycle, but they often fall short on FMAX (max clock frequency). Most of them will fold around 50 - 60 MHz for the C8 speed grade.

And for the FPGA platform we are looking for, we would like to see:

*) open source hardware

*) versatile with plenty of peripherals

*) expandable

*) software friendly

*) DFM

We have looked up and down, but couldn't find a perfect match yet. So we decided to go extra miles and do it by ourselves.

And a spy photo of this board can be found here

We original decided on the name Mustang Duino, but later we took some marketing advice and named it PulseRain M10, because:
‚Äč

A) It has an Altera MAX 10 FPGA on board. On the record, M is for MAX

B) Internally, we nickname FP51 as Mustang to honor the legendary Mustang Fighter-bomber in World War II. So off the record, M stands for Mustang.:-)


We made the form factor of this board to be Arduino compatible, and we support both 3.3V and 5V IO through jumper setting, so that both 3.3V and 5V shield can be mounted to our board. By itself, the board is 2.1 inch x 3.2 inch.

And the board has an Altera 10M08SAE144C8G FPGA, with onboard peripherals like

*) ADC
*) Temperature Sensing Diode
*) Serial SRAM
*) Voice Codec, (with onboard microphne and speaking plug)
*) MicroSD Card Socket

For more information, please go to m10.pulserain.com

The prototype of the board meets our expectations. And we are currently starting pilot run for production. Stay tuned!

    Posted by Changyi at 2:03 PM 0 Comments  

 NIOS II Processor in MAX 10 Device 9/11/2016

The Altera NIOS II (Gen 2) processor comes with MAX 10 device for free, sort of.

In fact, the NIOS II comes with two flavors: economical and fast. Unfortunately, it seems the latter needs a license while the former is truly free as free beer.

And the MAX 10 has very limited BRAMs. I found it not too hard to make bloated code that devour all the available BRAMs. In particular, please skimp on the usage of printf, and use small size C library if possible.

==============
PS: Warmest Condolences to those who lost their loved ones 15 years ago.

    Posted by Changyi at 12:32 AM 0 Comments  

 SDC Constraint, Input / Output Delay 8/26/2016

Preparing IO constraint for FPGA is always a tedious job. And the following is a spreadsheet to help the number crunching. BTW, I have to say that MS Excel is much more powerful than Google Spreadsheet.

    Posted by Changyi at 12:54 AM 0 Comments  

   

 

    

README

*) Legal Disclaimer
*) The Book

Links

*) PulseRain
*) GitHub
*) Forum


*) FCC Wireless
*) ARRL
*) PAPA System
*) EARS

Archives