This (private) project has been designed for these purposes:
a) Get a Programmer for the ATMEL AVR with USB Interface, as my laptop has no parallel / serial port. As all the ports are on feed through, it is also possible to programm the AVR to get a JTAG interface.
b) Get the possibility to play with several USB IC's: e.g.TUSB 3510 and FTDI 232BM. The TUSB is interesting, but there's no SW available, so as fallback the FTDI can be used)
c) Get a rapid prototyping board for the ATMEL AVR: a "daughter" board can be put on top of the board, and access all the ports of the Atmel.
Also it is possible to generate daughterboards for all the AVR's, so you are not limited to the 8515. With a little effort (JTAG Programming SW) also the new MCUs can be used....
Scalability was a goal, too
tobi (at) coldtobi (dot) de
USB Programmer by Tobias Frost "Copylefted" by Tobias Frost 2005 tobi (at) coldtobi.de Version: March 30th, 2005 Schematic-Version: 10/03/2005 (DD/MM/YYYY) (CVS 1.6) This USB Programmer has been entered into the Olimex PCB Pool Contest. This file describes the hardware, as because of lack of time (and build hardware) no software is availavle at this time. The schematic is done with the freeware Eagle Version, available at cadsoft.de. WARNING: I DO NOT HAVE TESTED THE SCHEMATIC YET. THEREFORE IT CAN BE, THAT IT WONT WORK OR EVEN DAMAGE SOMETHING (E.G YOUR COMPUTER)! USE AT YOUR OWN RISK! If you have any remarks or questions, please feel free to contact me. 1. License USB Programmer Design for the ATMEL AVR MCU Copyright (C) 2004 Tobias Frost This project is a free project; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This project is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this project; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA02111-1307USA Additionally to the GPL: If you are programming for this project - a TUSB device driver (TUSB firmware or/and PC-Side driver) - a FDTI bit banging device driver that you also place this drivers under GPL, and therefore make the source available. (As I designed the board for free, I think I can expect everyone using this project will understand, that if you take you can also give.) If you unable to open your work, please contact me. I am sure that we can find a solution. Also if you want to commercially resale the board, please contact me. In other words: Any deviration from the license above needs my written permission. 2. Software At the moment, there is no software for this project. But as this project is very generic, this is no limitation for the usability, as it is designed to work as as "development" board. But there are plans to programm some kind of firmware, with this support: - Programming AVRs "incircuit" PC driver/application for the TUSB or the FTDI ("Bit Banging Mode") would be required to do this. All the needed pins are routed to the chip (HELP WANTED) - Programming Software for programming a controller on a daughter board. First the "old" AVRs are interesting, but also JTAG programming would be really nice.. The AVR SW should take the data using the RX/TX Interface of the USB Chips, and the protocol compatible to the AVR Studio. For these tasks, PC device drivers are available for the FTDI, (Windows and Linux), so there should be only need for the AVR SW. If you like to volunteer to participate in programming, please contact me! Soon I will put the project's information on my website, so please visit "www.coldtobi.de/usbprog/", or mail to "email@example.com" to get informed, as soon the website gets online. 3. Hardware This is the main part of the docmument: A hopefully not so short description of the hardware. Generally, my design uses SMT (Surface mounted technology) heavily. This was because I like this more than THT (through hole technology) as I hate to drill a lot.... Also, some of the parts are not available in THT, especially that USB IC's I use. But (may with exception of these ICs), I use only "1206" or "0805" SMDs, and they are easy to handle. All you need is a fine soldering iron, thin solder and a tweezer. Let's start with the hardware... 3.1 Power Supply The design is "Bus powered". The IC1 is a linear voltage regulator, making from the USB 5V the at some points required 3V3. Nothing special at this point. Signals: Description USB-5V 5V from USB Bus. 3V3 Regulated 3.3 V GND Ground Note: There is no reverse voltage protection. This should be not a problem, as USB is keyed. Note2: Do _NEVER_ inject power into the USB bus. This can damage your computer. Note3: Only power small loads from the USB. If using more than 100mA in total, make sure you are familiar with the USB Specs... 3.2 USB Connector The connector connects (as the word says) the board from the USB bus to the transceiver IC's. I used a SAMTEC Connector, as it was the only one with SMD-pins I was able to obtain. Only one transceiver can be used at one time, so I introduced several jumpers to route the signals. Please solder the jumper in that way, that the signal "goes" to the right IC. The signals at the jumper prefixed with "T" go to the TUSB, the "F" ones to the FTDI. The jumpers' middle pins are connected to the USB Connector, Pin 1 is connected to the TUSB, Pin 3 to the FTDI. Signal Jumper Description D+ SJ7 The "+" Data Signal of the USB D- SJ8 The "-" Data Signal 3.3 TUSB 3510 The manufactor of this USB Interface is Texas Instruments. This USB Controller has an 8051 compatible MCU core, and has to be programmed to be functional. Unfortunaltly, the documentation about the controller is not very detailed, so I expect some work to compelete the TUSB-side driver. However, I found on the net an example implementation of a sample driver from Bodo Rzany. I will add this driver to this package, so please look out for the file "tusb3410-firmware.tgz". 3.3.1 TUSB support parts The schematic incorporating the TUSB is mainly taken from the data sheet. So the suspend schematic is also applied (See datasheet, section Application Notes) Also, all pins are accessible, as all are connected to SMD-Pads. If you need -- as an example -- remote wakeup, it's possible. Now, a special note on the Diodes D3 to D8: As the TUSB operates on 3.3 V only, As the AVR can operate on 5V, the inputs have to be protected. This is done with these diodes, as they should have a zener voltage of 3.3 Volts. The current is limited by the resitors later toward the AVR. Even if the AVR is operated on 5V, the 3.3V are sufficient for the AVR to receive a logical "High". The crystal's frequency is 12MHz. Please refer to the datasheet for details! 3.3.2 TUSB EEPROM Interface The TUSB can load it's programm over the bus and using a SPI EEPROM. As I do not plan to use this feature, but to be open as possible all signals are accessable: The part "SV8" gives access to SCLK, SDATA, 3.3V and GND. See the schematic for details. 3.3.3 TUSB Serial Lines The TUSB has a built in serial port with all the needed support ports. The signals are prefixed "T" for TUSB and not all used for the AVR connection described below. 3.3.3 TUSB's DIO The TUSB has 4 DIOS (Digital Input/Output). In my design, these port are connected to programm the AVR. Details are in the "AVR Connection" Chapter, below. The table only shows the connection, if the jumpers are soldered correctly. TUSB AVR I/O Function P3_0 MOSI I/O MOSI Pin P3_1 MISO I/O MISO Pin P3_3 TRESET I/O Reset Pin (Must be set to "high" in "normal operation") P3_4 TSCK I/O SCLK Pin 3.4 FTDI 232BM The FTDI 232BM is a USB-to-serial convertor chip. The manufactor is FTDI (www.ftdichip.com). Note: This chip is the second generation of the USB Transeiver! This chip has no microcontroller included, but should offer the same functionality as the TUSB built into silicon: - Serial convertor (USB->RS232) - "Bit Banging" inteface (Programming the AVR over USB) For the first feature, there are drivers available. For Windows from the manufactor, and for linux there's kernel support. (AFAIK a kernel of 2.4.xx or later is ok) For the second feature, there MIGHT be some programming effort necessary, and I heard, that this feature is again not well documentated. The Jumper SJ10 sets the IO-Voltage of the IC. Please set it to the appropiate Voltage, probably the AVR Voltage: SJ10: 3.3V 1-2 closed 5V 2-3 closed 3.4.1 FTDI Support Parts Also, this chip has needs some parts. For these, I also used the datasheet to develop it. The crystal to be used should be 6 MHz. The C7 and C8 crystal loads are in the area of 27pF. 3.4.2 EEPROM Also this IC can get its USB Configuration from a external EERPOM. This time, the EEPROM is a SPI one. Please read the Datasheet for an example who to connect the EEPROM and what types are supported. See the schematic for the EECS, EESK and EEDATA pins. They are connected on the Board to SMD-Pads, NOTE: 3.4.3 Serial Connection The FTDI Serial Cell is connected as described below in the AVR Connection Section. The control lines are not used in the design. They are prepared to be used in the "Bit Banging Mode" to programm the AVR. FTDI-Pin AVR FDTI-Function Description RTS MOSI OUT MOSI DTR SCK OUT SCK DSR MISO IN MISO DCD RESET IN RESET. Erronous connected. See Errata below! 3.4.4 Bit Banging Interface To programm the onboard AVR, the Bit Banging Mode can be used. As aleady stated, this needs software to support this. However, in the AVR Connection Section, this is detailed. 4. AVR The AVR 8515 has been put on a socket, and therefore can be replaced. Also it is possible, that no controller is used. For example, in this case a "daughter board" can be used to connect another controller, The AVR has its own crystal and is connected to the USB circuit via the serial interface and/or the built in SPI Interface, also usable for in-circuit reprogramming. It is possible to power the AVR with different voltages: 3V3, 5V and external power. This is determined by SJ9: 5V 1-2 closed (2-3 open) 3V3 2-3 closed (1-2 open) external Jumper open. External power applied though SV6 and SV7. Please set 5. Jumpers and AVR Inter-Connection As already noted, one USB Chip can be used at a time. To get the signals to the AVR, several jumpers should be set To connect to the TUSB, the "T"-Prefixed signals has to be routed to the "AVR"-Prefixed-Signals. This is done with shorting Pins 2 and 3. To use the FTDI, short pins 1 and 2. The following table gives a summary about the important jumpers. Serial: SJ5 "AVR Rx" SJ6 "AVR Tx" SPI programming interface : SJ1 "AVR Reset" SJ2 "AVR MOSI" SJ3 "AVR MISO" SJ4 "AVR SCK" USB Input: SJ7 "USB Data +" (Note: 1-2 is TUSB, 2-3 is FTDI here) SJ8 "USB Data -" (Note: 1-2 is TUSB, 2-3 is FTDI here) ERRATA: Flaws that are found after giving the board to the contest... 1. Flaw: The FTDI's PWRCTL Pin should not be tied to F3V3 in any circumstances. According to the datasheet, it should be connected to VCIO So, if you are using 5V as I/O Voltage, the pin is not connected to the right voltage. Fix: Better would be connecting to VCIO Best would be a jumper with the options GND and VCIO Workaround: - Use 3V3 as IO-Voltage OR - Ripup the F3V3 line at pin 14 of the IC, and connect it to pin 13.... Description: The pin PWCTL determines, if we are self-powered or bus-powered. If the pin is at VCIO, we are self powered, else we are bus-powered. If you set VCIO to 5V, the pin is at 3V3,a 2. Flaw: There should be a serial resistance in the D+ and D- Path, at least for the FTDI Fix: Instead of shorting the jumper at D+ and D-, solder in a 22 Ohm resistor Description: This was in the FTDI-Datasheet. I think it will work without it, but as the correction is that easy, it should be done this way.... 3. Flaw The names of the FTDI-EEPROM-Connection-SMD-Pads are wrong. They have been copied and then forgotten to be renamed. So if you see the pads TXLED1 RXLED1 and TXDEN1 (note the extra "1" at the end of the name), they are for the EEPROM: TXLED1 -- EESK RXLED1 -- EEDATA TXDEN1 -- EECS 4. Flaw The FTDI BitBanging Pin for RESET is not usable for this purpose, as this is a input pin. Workaround: Connect "TXDEN" to "DCD". Fortunaltly TXDEN has a SMD-Pad and DCD has a via nearby.... (Note: This is only a problem, if someone developes a bit banging device driver....)