Alexan's Electronic Drum Kit: A Review

Recently, I am planning to buy a drum set just for home use. But I remembered that Alexan has an Electronics Drum Set and I want to give it a try.

So I rushed at Alexan and bought an Alexan's Drum Set for 600+Pesos.

Building it is fairly easy as the schematic is already provided. However, there are some values not listed on the BOM of the schematic like the capacitor in the kit I bought. And there are traces that are shorted on the PCB (luckily, I used a bench power supply that has an Over Current Protection).

Here is the final assembled piece:

There is an output for the amplifier and there is a provided built-in amplifier section in the schematic for the mini speaker. (driven by LM386)

I would probably say that the sound quality using the provided speaker is good vs the price of the kit. I tried putting it in an amplifier and it is ok as well. Maybe this December, me and my former band mates will meet, and will try to use this one hooked up on an amplifier and will post the results here.

Wireless Controller Firmware Mod

Here is a Long-Range Wireless Controller from China bought by my friend Jay. This is mainly used for Pyro Shows (but I have other plans for it in the future). The package includes a Transmitter and a Receiver:



This features 8 Momentary and 4 Latch Setting for the 12 relays. I was requested to use the existing board and create a customized program for the PIC16F57 built into it. The program must have the following features:
1. manual mode
2. 32 cues sequencer mode
3. step firing mode

I quickly checked the datasheet of the ICs used (PT2272 and PIC16F57) to be able to reverse engineer and create a schematic out of the PCB connection traces. (The schematic is still written on paper, but I have plans to create an Eagle Schematic for it). After the schematic was drawn, I notice a jumper. It was connected on the RB0 of the PIC and I decided to use this jumper to switch from manual to sequencer mode.



Fast-forwarding the development phase of the firmware development for the PIC16F57, I was able to finish it quickly. The firmware was written from scratch and I was able to replicate the old feature + (PLUS!) the new features that was requested to me.

The PIC's oscillator clock source was changed as well to be able to accomodate a very accurate timing increment. And here is the completed board (with test LEDs):

Here is a video demonstration of the manual mode. Then I removed the jumper, power off, power on, then pressed a button to demonstrate the sequencer mode (this is the Firmware (FW) version 00.08.00).
http://img4.imageshack.us/i/moviei.mp4/

Here is another sequencer mode with LEDs (FW revision 00.08.08).
http://img214.imageshack.us/i/movie0001.mp4/

And this is the final version with Step Firing Mode (FW revision 00.08.09 - the version as of this writing)
http://img37.imageshack.us/i/moviev.mp4/

As for the conclusion of the project:
1. The board has now more features than it was before.
2. Sequencer mode and the Step Firing mode works very well (with 40msec holding for relays)

This is just a start, as I have more ideas for this board... :)

Update as of Dec. 4, 2009:
Deadman's Switch was added on the sequencer mode. Current version is 00.08.10.

Recovering My Asus EEE's Corrupted BIOS: The hard (but cost-effective) way

(this is my post from a forum dated September 05, 2009, I am just reposting it here)

Hello,

As of yesterday, I pulled out my Asus EEE from Asus service center due to very high repair cost. Almost 200USD around 10,000pesos... But.... I am so happy that I had revived my Asus EEE... As from my story, the bootblock was erased and I tried all the tricks for bootblock recovery techniques I found on the net and without luck.

It took me two complete days to recover this little machine in a hard way. I opened my Asus EEE PC with the steps here: http://forum.eeeuser.com/viewtopic.php?id=6036

Then I saw the BIOS IC and removed it from the board using a soldering iron

From there, I obtained a datasheet from Winbond W25X40 4M-Bit Flash and read and studied all the instructions. From there, I developed the circuit, firmware, and software for flashing. Here is the software created in C# I had just created this morning to flash my BIOS:

Here is the circuit I created (on breadboard hehe). I used a PIC16f628A (through UART @115200bps) because my parallel port is already damaged. Used SDCC as the compiler.

After programming and verifying using the software I created, I tried to temporarily wire it to see if it works:

And it worked!

My Asus EEE is up and running again!

I am so happy!!! ^_^


Update (Dec 4 2009):

I had just updated my BIOS Flasher to version 00.08.02 (written in C#)

Update (Jan 17, 2016):

I updated this entry due to deletion of image from ImageShack's server.

Update (Sep 3, 2016)

The firmware source code for the PIC16F628A BIOS programmer is in Github: Link

Globe Tattoo's USB HSDPA Modem:Interfacing to C#: (Continuation)

Here is the short sample C# code I did for the Globe USB HSDPA using Visual C# 2008:

Here is the output:

Interfacing Globe Tattoo's HSDPA Modem to Hyperterminal

I have a project wherein I need a GSM Modem to be interfaced with my Computer and do some data gathering. AND I need a low cost solution because GSM Modems are really expensive. Then, I saw my sister's Huawei Globe Tattoo and asked myself if it can communicate with AT command. I immediately performed some basic experiments (sending and receive SMS) and it worked! I was able to quickly communicate with it using Hyperterminal and was able to create my first program with it using Visual C#. It was really a big cost saving!

I would like to share the procedure on how to interface Globe Tattoo's HSDPA Modem Hyperterminal:

1. Go to device manager and check for the Com number of the USB Modem.

2. Open hyperterminal and connect to the Com Port indicated on the Device Manager.

3. On Port Settings, click ok.

4. Go to File>Properties>Settings>Ascii Setup... Check "echo typed characters locally."

5. Issue AT Commands!

Advantage:

1. cheap alternative to RS232 GSM Modems (my sister bought the USB Modem for 1,900+Pesos. As of this writing, the price is around 800+pesos only)
2. USB Interface, no external power needed

One disadvantage is the difficulty to be interfaced with microcontrollers where I recommend using a TTL/RS-232 GSM modems like this very good GSM kit from E-Gizmo  Link .

This is a low-cost solution for students who needs SMS capability for their thesis (PC-based projects).