Laine's Super Interesting Blog

Using OpenOCD with the Actel SmartFusion Eval Board

lwalkera — Sun, 10 Apr 2011 06:52:50 +0000

I just got this new SmartFusion Evaluation board from Actel. On it is a cool chip that a combination FPGA, analog processor, and Cortex-M3 microcontroller. The board has a built-in JTAG programmer that uses the Actel toolchain to download new designs into the chip, which is pretty nice. However, you can’t debug the software on the microcontroller with it.

So I decided to see if I could get OpenOCD working with my Olimex JTAG-Tiny USB JTAG tool, since there was a 20-pin ARM JTAG header on the board as well. On the first go, it didn’t work, so I decided to look at the signals on my ‘scope. Turns out that the TRST and TCK lines were wiggling, but only at about 1V when they should have been at around 3.3V. I downloaded the schematics from the Actel site, and this is what I found:

SmartFusion Eval Board JTAG Circuit

Turns out that those lines had very strong pull-downs on them. Coupled with the 330 ohm, series output resistors, these pull-downs created a voltage divider that was pulling the signal down to around the 1-2V level.

So I fired up my soldering iron, and replaced the resistors with some 4.3k ohm resistors that I had near my desk. And after hooking everything back up, I was able to halt the processor and look around in memory.

Hopefully I’ll be able to get the eNVM flashing over JTAG working in OpenOCD soon.

TL;DR: Remove R14 & R15 and replace with >5k ohm resistors.

HVAC Controller Progress

lwalkera — Mon, 13 Sep 2010 02:04:51 +0000

I got boards back from BatchPCB and have almost fully populated one. Digikey sent me the wrong resisitors, so I have to see if I can get the right ones. Take a look:

There are a couple of problems with the layout that I need to fix in the next revision, but I should be able to get going. Now on to programming the darn thing!

Progress on the HVAC Controller

lwalkera — Tue, 24 Aug 2010 07:37:27 +0000

Some progress on the HVAC side of things. I got a preliminary circuit made and PCB in the works. I’m hopefully going to use this as an excuse to tinker around with the Arduino stuff. Take a look:

Once I get it working, I’ll release the designs and code.

Silencing of the Wii’s

lwalkera — Tue, 01 Jun 2010 10:42:19 +0000

So I went out and got the new Super Mario Galaxy 2 game the other day at Fry’s. I hadn’t hooked up my Wii in quite some some and I had to dig out my video capture card and audio cables to hook the Wii up to my computer. When I go to play the game, I’m greeted with an awful cracking caused by the clipping of the Wii’s audio as the System Menu plays its little intro sound. Somehow I had gotten it to play nice with my computer before, but it’s been so long, I’d forgotten. Having some spare time on my hands, I’d figure I’d fix the problem once and for all.

So I crack open my Wii, and get down to the motherboard. On the back, by the AV connector, I use my multimeter to find which pin corresponds to the audio outputs. I trace the wires back, and am pleasantly surprised by a nice couple of 0402 pads to ground (C107 & C106) right next to two series resistors (R64 & R63). Two words instantly popped into my head: Voltage Divider!

I measured the two series resistors to be 1k ohm. I happened to have a broken cable modem with 0402 parts laying around, so I scavenged a pair of 10k ohm resistors from it. I moved the 1k resistor to the corresponding pad that connects to ground, and installed the 10k resistors into the series position where the 1k’s had been. This should give me ~1/11 the voltage I had previously, assuming my sound doesn’t draw too much current from the Wii’s audio lines.

Wii motherboard after modding the audio output

So I put the heat sinks back on, and hook up the DVD drive, and low and behold: no more crackling! Yay!

For the tldr folks, the steps to quiet your Wii are:

Disassemble your Wii and remove the motherboard
Remove and keep the two 1k resistors R63 & R64
Resolder the 1k resistors to the pads for C106 & C107
Get some 10k resistors, and solder them onto the R63 & R64 pads
Put the heatsinks back on, plug in the DVD drive, and see if the Wii still works
Reassemble fully if working and enjoy!

Note that I take no responsibility for what you do to your Wii. This will void your warranty!

Restoring old firmware on a Dlink DCM-202

lwalkera — Sun, 28 Mar 2010 01:23:45 +0000

If you’re like me and tried to upgrade your Dlink DCM-202 firmware only to find out that afterwards the telnet shell is no longer accessible, then this is the guide for you. I’ll describe how to recover the old version of the firmware so that you can try other firmwares as they become available.

WARNING!!: This procedure will void your warranty, and may fry your board! I take no responsibility to what you do to your board. Use this guide AT YOUR OWN RISK!!!

To do this procedure you’ll need a TTL 3.3V serial adapter to talk with the bootloader. I used a small Bluetooth to serial board with built-in level translators that I had around, but you’ll probably want to use something like the FTDI TTL serial to USB cable.

The first step to downgrading your DCM-202, to crack open the case and take the circuit board out. You should see something like this on the back:

To recover the old firmware you’ll need to short the via highlighted in red, to the ground plane next to it while turning on the power to the board. This will hold one of the address lines to the flash ROM (the chip to the left of the image) low so that it’ll cause a checksum error when the bootloader tries to load the firmware, but won’t interfere with the bootloader which is also in flash. Note that, depending on your board, you may have to scrape off some of the green solder-mask to get to the metal underneath.

Here’s a listing of the serial output when booting normally:

Power-On
Uncompressing Image...
Application 1 Booting...

D-Link DCM-202 Running..

Model: DCM-202
Hardware version: 1A
Chip ID: PUMA-S
Speed: 125.00 MHz
Software version: 2.00.03D1.06
Bootloader version: 1.0.3
Build date: Jun 16 2009/10:34:45
System Object ID: ############
MAC Address: ############
Tuner Type: MicroTune MT2050

<<>>      <<>>
0x947ffdf0 (tRootTask): tnetd53xx_emac_phy_run_autoneg(0, 0x000102c7)
0x947ffdf0 (tRootTask): tnetd53xx_emac_phy_run_autoneg(0, 0x000102c7)
0x9477bea0 (tNetTask): tnetd53xx_emac_phy_run_autoneg(0, 0x000002c7)
0x9477bea0 (tNetTask): TNETD53XX_EMAC_MAC_CONTROL = 768
0x9477bea0 (tNetTask): TNETD53XX_EMAC_PHY_REG_GEN_CTL = 0x3100
0x9477bea0 (tNetTask): TNETD53XX_EMAC_PHY_REG_GEN_STS = 0x786d
Initializing Cable Modem DS/US Registers

And when resetting with that signal shorted it displays a boot menu that allows you to download a new image over the serial line using the xmodem protocol, or to select one of the two firmware images in the flash. The image named “Application 1″ should be your old firmware, so all you have to do to boot it up is type in “1″ and hit enter:

SW Reset SWR0
Uncompressing Image...
CRC32 error!

Uncompressing Image...
CRC32 error!

Uncompressing Image...
CRC32 error!

Unable to load Image1 or Image2

Micro Bootloader Version: 1.0.3

MENU
---------------------------
0>XMODEM receive then run
1>Application 1
2>Application 2
3>XMODEM send storage image
---------------------------
SELECT: 1

Uncompressing Image...
Application 1 Booting...

D-LINK DCM-202 Running..

Model: DCM-202
Hardware version: 1A
Chip ID: PUMA-S
Speed: 125.00 MHz
Software version: 2.00.03D1.07
Bootloader version: 1.0.3
Build date: Jul 22 2009/15:00:46
System Object ID: ###############
MAC Address: ##############
Tuner Type: MicroTune MT2050

<<>>      <<>>
0x947ffdf0 (tRootTask): tnetd53xx_emac_phy_run_autoneg(0, 0x000102c7)
Setting default sector to 1
Initializing Cable Modem DS/US Registers

0x9477bea0 (tNetTask): tnetd53xx_emac_phy_run_autoneg(0, 0x000002c7)
0x9477bea0 (tNetTask): TNETD53XX_EMAC_MAC_CONTROL = 768
0x9477bea0 (tNetTask): TNETD53XX_EMAC_PHY_REG_GEN_CTL = 0x1100
0x9477bea0 (tNetTask): TNETD53XX_EMAC_PHY_REG_GEN_STS = 0x786d
Initializing Cable Modem DS/US Registers

After that you should have your old firmware running and be able to telnet in once again. If you have any questions, just leave a comment and I’ll try to answer it.

More Notes

lwalkera — Mon, 16 Nov 2009 09:15:07 +0000

Specs for the LEDs used for the backlight in the stock display unit:

V_f = 3.7 V
I @ V_f = 18.3 mA

Truth-table for the Mode feedback signals (1=open):

	Vent	Vent+Floor	Floor	Floor+Defrost	Defrost
Mode 1	0	1	1	0	0
Mode 2	1	1	0	0	1
Mode 3	1	0	0	1	0
Mode 4	0	0	1	1	1

Accord ’06 Carputer – Schematics and Pinouts

lwalkera — Mon, 28 Sep 2009 06:53:09 +0000

For my own information these are the block schematic diagrams of the HVAC system and pinout of the 22-pin connector that controls all the fans and flap motors.

Pinout for the 22-Pin HVAC Connection (Green)
Pin	Wire Color	Signal
1	Blue	A/C Pressure(Enable) Switch	Output (Active Low)
2	Red/Yellow	Mode 1	Input (Active Grounded to pin 9)
3	Red/Blue	Mode 2	Input (Active Grounded to pin 9)
4	White/Blue	Mode 3	Input (Active Grounded to pin 9)
5	Yellow/Green	Mode 4	Input (Active Grounded to pin 9)
6	Yellow/Black	Rear Window Defogger Relay	Output (Active Low)
7	Light Green/Red	Air Source Motor (Recirculate Direction)	Output (Active Low)
8	Green/White	Air Source Motor (Fresh Direction)	Output (Active Low)
9	Red/Black	Sensor Common Ground	Output (Tie to Pin 22)
10	Brown	A/C Evaporator NTC Thermistor	Input
11	Yellow/Red	Mode Flap Motor (Vent Direction)	Output (+12V and Gnd on pin 12)
12	Yellow/Blue	Mode Flap Motor (Defrost Direction)	Output (+12V and Gnd on pin 11)
13	Pink/Blue	Air Mix Flap Motor (Hot Direction)	Output (+12V and Gnd on pin 14)
14	Green	Air Mix Flap Motor (Cool Direction)	Output (+12V and Gnd on pin 13)
15	Blue/Red	Blower BJT Collector	Input
16	Blue/Yellow	Blower Power BJT Base	Output
17	Pink/Black	Air Mix Potential	Input (Center tap of Pot. ~0.5V-4.5V)
18	Gray	Air Mix Potential +5V	Output (Tie to +5V)
19	N/C	N/C	N/C
20	Black/Yellow	IG2 (Battery Power +12V)	Input
21	N/C	N/C	N/C
22	Black	Ground (G503)	Input

New Project – Accord ’06 Carputer

lwalkera — Mon, 28 Sep 2009 04:57:06 +0000

So, I’ve been toying around with the idea of making my own carputer ever since I got my first car. I’ve decided to actually do it now that I actually have the time/money to do so. Most of the stuff I’m probably going to be posting is just my own notes so I can keep them in one place. Feel free to comment about anything and let me know if you have any ideas that might help.

My basic plan is to take a stock headunit (so I can keep the buttons and dials) and add a touchscreen to control a small embedded PC, probably an ARM based one running Linux.

To start off here is the used headunit I got off of eBay that I’m going to mod:

I’m planning on cutting out the old screen and the buttons below it and putting in a 5.7″ touchscreen which seem to fit perfectly. I started out with another headunit, but had the wrong type of climate control. Here’s a picture of that one with the hole cut out for the touch screen:

I’m planning on filling in the extra space around the screen with Bondo or fiberglass and spray-painting the silver part the same silver color.

Carbonation!

lwalkera — Sat, 20 Jun 2009 03:36:15 +0000

I picked up some cool stuff today from the local home-brew shop in Sac. Take a look:

Carbonation setup

After getting a pipe wrench and some teflon tape I was able to make some fizzy blue drinks:

Fizzies

I predict much fun experimenting with making various drinks fizzy.

Hello World!

lwalkera — Fri, 19 Jun 2009 03:39:48 +0000

Well I thought it was about time to get around to this blogging thing. There probably won’t be a lot of updates but we’ll see where it goes. Feel free to e-mail if you find any of this interesting and want some more info.