Comments on: An Arduino Compatible Using CP2102

By: kwong

kwong — Wed, 24 Apr 2013 12:25:09 +0000

Hi Pieter,

C4 is the USB power bypassing cap, it needs to be placed as close to the USB connector as possible. C8 is the FT232RL 3V3 bypassing cap, and needs to be placed as close to pin 17 of the chip as possible. C10 and C13 are not as critical (C10 is to provide power reset timing delay and C13 is used to generate the reset signal required by the ATmega328P).

By: Pieter

Pieter — Wed, 24 Apr 2013 10:25:08 +0000

I’m thinking of designing a minimum breakout board for the FT232RL that will plug into an ATMega328 Project Board like a small “shield” (stil have to design that part).

Looking at the Duemilanove Schematic (http://arduino.cc/en/uploads/Main/arduino-duemilanove-schematic.pdf), Which of the Capacitors on the USB side (C4, C8, C10) needs to be on the breakout board and close to their respective pins on the FT232RL chip? …does Capacitor C13 need to be close to the FT232RL chip or the Microcontroller chip? (or neither?)

By: kwong

kwong — Wed, 20 Feb 2013 00:35:01 +0000

Hi Daniel,

I have been using the CP2102 board for a while now (both with Linux and Windows) and it has been working really well. Since it is just a USB to UART converter, no special software is needed Linux. For Windows, you will need the driver from silab (http://www.silabs.com/products/mcu/Pages/USBtoUARTBridgeVCPDrivers.aspx).

If you built the circuit according to what I have, then it should work (The 100nf cap to the RESET pin on the ATmega328 is essential as ATmega328 needs to be reset right before the upload begins, according to the Arduino bootloader design). The Arduino bootloader I used is the standard Duemilanove bootloader if this helps.

By: Daniel

Daniel — Tue, 19 Feb 2013 21:52:34 +0000

Your page is the best source I can find regarding a CP2102.

When I built my diy 328p board it seems it came with the blink sketch already. Tried to update the blink sketch, the chip resets and the L.E.D blinks fast a few times, but the sketch doesn’t update…

Have you tried with Xp? Do you know settings for sketch to make the CP2102 work?

Thanks! great page!!

By: Pieter

Pieter — Thu, 07 Feb 2013 18:31:45 +0000

Thanx, that clears it up. Don’t know if I’m ready to solder a SSOP-28 yet though…

Will the following board work in the mean time? (http://www.mantech.co.za/datasheets/products/PMOD-USBUART_D.pdf) …or will the 3.3V be a problem?

By: kwong

kwong — Thu, 07 Feb 2013 16:13:21 +0000

Hi Pieter,

Thanks for your comment. I don’t have an FT232RL chip right now, but if you take a look at the schematic for Arduino Duemilanove (http://arduino.cc/en/uploads/Main/arduino-duemilanove-schematic.pdf) you will see that the FT232RL portion of the circuit.

Basically, you will need C4, C8, C10, RTS, C13 as a bare minimum. Pin 1 and Pin 5 (Rx, Tx) of FT232RL along with the reset signal (via R2, C13 to ATmega328′s reset pin) will be used to communicate with Arduino’s UART port (D0, D1). Hopefully this helps.

By: Pieter

Pieter — Thu, 07 Feb 2013 15:01:58 +0000

Hi Kerry, I always love reading your articles =)

I want to get started with Arduino and found the following project board I’m thinking of buying or clone-ing (http://www.mantech.co.za/datasheets/products/PC14-006-01.pdf).

I was wondering if you can do a similar thread to this one, but showing how to interface the FT232R with the ATMega328 instead of CP2102…?

Thanx in advance and keep up the good work!

By: An Arduino Compatible Using CP2102 « Meteo

An Arduino Compatible Using CP2102 « Meteo — Tue, 03 Apr 2012 12:41:36 +0000

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By: kwong

kwong — Sun, 19 Feb 2012 02:06:30 +0000

Assuming that you want to use Arduino on your ATmega328p, I’d recommend you reading http://arduino.cc/en/Tutorial/ArduinoISP to get an idea of how to bootloading your Arduino. If you are using ICSP method (e.g. the method I used here http://www.kerrywong.com/2010/04/02/on-atmega328-bootloading-with-ftdi-bitbang-method/), you could load your program without having to use a bootloader.

Check out the Arduino forum, there are a lot of examples there. Good luck.

By: jagadeshwaran

jagadeshwaran — Sun, 19 Feb 2012 02:00:47 +0000

HI
what is a boot loader and how to load the boot loader in atmega328p.I bought atmega328p ic from sparkfun without the arduino boot loader now i want to load the boot loader please help me im breking my heads
.

By: Varma Naidu V

Varma Naidu V — Tue, 03 Jan 2012 13:21:42 +0000

:) it worked. Now I have one more query. How to change the product description string in the EEPROM?

Could you please help me on this?

By: kwong

kwong — Fri, 30 Dec 2011 22:12:10 +0000

You can take a look at a tutorial I did a while ago (http://www.kerrywong.com/2011/09/25/hand-soldering-fine-pitch-lga-chip/), it’s not the easiest thing in the world but definitely doable.

By: Varma Naidu V

Varma Naidu V — Fri, 30 Dec 2011 09:01:35 +0000

Hi, I tried soldering by the way you did. But I am getting a short circuit between the pins. how did you solder the way its shown in the picture.
Thank you in anticipation

By: Varma Naidu V

Varma Naidu V — Fri, 30 Dec 2011 08:05:07 +0000

Thank you, I will follow your circuit diagram.
But one thing that amuses me is that, how did you solder those wires onto it? I tried but was unable to. so I am getting a breakout board for that

By: kwong

kwong — Wed, 28 Dec 2011 21:22:30 +0000

This is directly from the reference design and it works pretty well. Other more complex designs may offer more functions (e.g. 3.3v/5v) as this particular one is 5V only.