yamppPod MP3
This page is related to the yamppPod (yPod) MP3 player project of Jesper Hansen at www.yampp.com
The hardware of this player is based around an Atmel ARM7, here AT90SAM7S128 and the VLSI VS1033 MPEG3 codec. Powered by a single LiIo/LiPo battery, the player also includes a color LCD, a 5-way switch for user inputs and a TWI EEPROM to store settings. A Micro SD card slot provides access to the music and system files stored a simple Micro SD card. Recharging the battery as well as data exchange with a PC is done by the USB interface available via mini-USB connector. A 3.5mm stereo jack provides the audio signal for headphones or any kind of amplifier.
And everything located on a tiny 4-layer PCB.
Please DO NOT ask me for layout files PCB’s and so on!!! This is NOT my own hardware design!!!
Hardware specifications
| General | |
| Memory Type | T-Flash (Micro-SD) card |
| Memory Capacity | Depend on T-Flash card |
| Playback formats | MP3, WMA, AAC, WAV |
| Power Supply | Li-Ion Plymer cell, 650 mAh. Charged via USB. |
| Playing time | 7-8 hours minimum |
| Display | 131*131 Color LCD, 1.6″, 4096 colors, LED backlight |
| Control | One Slide/Push button, 5 functions |
| External Interface | USB 2.0 Full Speed (12 Mbps) , Mass Storage Class |
| Internal Interface | JTAG, RS232 |
| Firmware Update | via USB bootloader |
| Physical data | |
| Dimensions | 65*45*14 (mm) |
| Weight | 61 g |
| Enclosure | Anodised aluminum, 5 colors |
| Audio Specifications | |
| Output Power | 35mW |
| S/N | >70 dB |
| Dynamic Range | 90dB |
| THD | 0.1 % |
| Frequency response | -0.1 dB |
For easy firmware development Jesper provides a simple development board with USB interface. The board provides access to the JTAG and RS232 interface for programming and debugging. This development board is compatible with the free and open On-Chip Debugging, In-System Programming “OpenOCD“. Firmware development is based on the free and open GNU-ARM tool chain Yagarto from http://www.yagarto.de For now there exist two firmware versions, one based on Jespers initial code and the second one I will provide. Both firmware are free and open source.
Check out both firmwares and play around to discovers all the differences, pro’s and contra’s.
Hardware Pictures
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Mictronics Firmware – GUI
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yamppPod RTC mod
This was the first modification of Jespers yPod hardware. I made this mod to add a real time clock to the player to show time and date. The mod requires only two addtional components, the DS1337 RTC chip and a crystal. Some additional connections to provide the periodical 1s interrupt, the alarm interrupt to the main controller and backup-power to the DS1337. The RTC chip is mounted on top of the TWI EEPROM, with almost same pinout, the wiring for SCL, SDA and GND is easy. Please note if you plan to add this mode, the DS1337 requires a crystal with a specified load capacitance (CL) of 6pF or close to to this. Otherwise it will be very unaccurate. See the datasheet for details.
Related Link
- www.yampp.com – Homepage of Jesper Hansen
- yamppPod discussion forum - Discussion forum where you can talk about anyhting related to the yPod
- yamppPod documentation page – Doxygen documentation, yPod reference guide, SVN access for Jespers firmware, additional tools
- Mictronics firmware SVN – Trunk version
