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Messages - RJSC

2
Project development, ideas, and suggestions / Re: Dangerous component/part tester
[quote author="ian"]@RJSC - I guess the thing that stumps me is that no additional math is needed to get uH value? I guess maybe that is why 470 is an important value, but they actually seen to use 100 in the code.[/quote]

Thats the mystery...
I'm very good with conceptual and qualitative thinking, but math and asm, not quite so...
3
Project development, ideas, and suggestions / Re: Dangerous component/part tester
[quote author="ian"]I'm obviously missing something key - that seems to just count till the pin goes low?[/quote]

And it should work in theory.
If you connect an inductor to ground with a pull-up resistor the current will ramp up.
The greater the current, the greater the voltage drop on the resistor will be, at some point in time, it will drop enough for the pin to read low.
4
Project development, ideas, and suggestions / Re: Dangerous component/part tester
[quote author="arupbsk"]@RJSC,
MOSFETs are great. But think of the price. At singles BC548/BC558 are priced at 1Re each (~2 US cents). There are some N channel SOT 23-5 MOSFETs in around the price (within 5cents) and P channels (~15 cents).
If we look at through hole MOSFET, market is worse.
Otherwise MOSFET is a great replacement to the BJT useed there.[/quote]

If it works, 1USD extra in parts is not bad, if we're not trying to make big profits, it just adds 1 USD to the final price.
5
Project development, ideas, and suggestions / Re: Dangerous component/part tester
[quote author="arupbsk"]
I've seen that the resistor measurements are having some 2% errors. The reason is revealed also. The transistors drop few milivolts, and the voltage drop depends on the DUT resistor's value. I get absolute error-free reading if I short the selected range's transistor, or calculate resistance with the actual pullup VCC that is in the R1-R2 network.[/quote]

Use mosfets instead of bipolar transistors. Once switched on they behave like a resistor with a few milli ohms (the RDSon parameter from the datasheet).
6
Project development, ideas, and suggestions / Re: Dangerous component/part tester
[quote author="arupbsk"]I saw some unexpected operations such as UART operations. I am unsure why the author is using UART. Also the project was done through AVRstudio. [/quote]

Don't worry about it! It outputs the same information of the LCD at 2400 bps 8N1.

I found it on a post on a German forum from the author: http://http://www.mikrocontroller.net/topic/131804#1658285
Quote
I have a new version:
Now, all languages should work (before, all lamguages except German
didn't work properly).
And I added a software UART that sends all the test results. It sends
almost the same data as shown on the LCD, except the characters which
are not implemented in the standard ASCII character set (for example the
"Omega" sign).
The UART output is PC3 (Pin 26 of the ATMega8).
The properties of the UART:
2400 baud
8 data bits
1 stop bit
no parity, no handshake

The internal timing error of the UART is almost zero.
So, the RC oscillator of the ATMega8 may have up to +/-3% tolerance to
get a stable connection. And according to the datasheet, the oscillator
has a 3% tolerance at 5V , 25°C and 1.0MHz.
So, it should work in most cases.

And there are two hex files:
In one("TransistorTestNew_UART_not_inverted.hex), the UART sends in
"normal" mode, to connect it to a TTL level RS232 receiver or to a level
shifter like MAX232.
In the other file ("TransistorTestNew.hex"), the UART sends in inverted
mode, for direcly connecting it to the RxD pin of a PC's RS232 port or a
USB=>serial converter with a "normal" PC-level input/output.
This makes the level shifter obsolete.
This solution is a bit "dirty" because a logical one is just 0V, and
according the RS232 standard it should be between -3V and -15V.
But in most cases, it works without problems.

Latest precompiled firmware version at: http://http://frickelpower.bplaced.net/ctest/
7
Flashrom / Re: Adding Bus Pirate support to flashrom?
I have tried without specifying the chip and the result is the same, I get an "Unknown Device".
I just posted the command specifying the chip because it produces a much smaller verbose output to post here.
If I don't specify the chip, it tries every supported chip on the list, getting back the same erroneous response I get when I specify the chip each try it makes.
Now I can't test it anymore, the chip was flashed with a parallel port interface and is now soldered on the device.
8
Flashrom / Re: Adding Bus Pirate support to flashrom?
I'll try at someone's windows XP PC when I get a new chip.

Today I  accidentally powered it from the 5V rail, and now its is very unreliable, sometimes works on manual mode, sometimes is doesn't.

The datasheet states 2.7V - 3.6 V, so it must be toasted now.

Searching for a website to order a new EN25F16 (SOP 8), the cheapest I've found was about 7 USD + shipping, and mine came form an 11 USD (shipping included) micro video camera I was patching the firmware to remove a forced yellow overlay date.
With a flash chip costing more than 65% of a full device that happens to contain it, I prefer to buy a new one and keep the old PCB for parts!

Does any of you know of an website where to order an EN25F16 at an affordable price?

Thanks!
11
Flashrom / Re: Adding Bus Pirate support to flashrom?
I've upgraded to v 5.2, but I still can't understand why with flashrom this continues t fail.

Manual SPI mode:
Code: [Select]
m
1. HiZ
2. 1-WIRE
3. UART
4. I2C
5. SPI
6. 2WIRE
7. 3WIRE
8. KEYB
9. LCD
x. exit(without change)

(1)> 5
Set speed:
 1. 30KHz
 2. 125KHz
 3. 250KHz
 4. 1MHz

(1)> 4
Clock polarity:
 1. Idle low *default
 2. Idle high

(1)> 1
Output clock edge:
 1. Idle to active
 2. Active to idle *default

(2)> 1
Input sample phase:
 1. Middle *default
 2. End

(1)> 1
Select output type:
 1. Open drain (H=Hi-Z, L=GND)
 2. Normal (H=3.3V, L=GND)

(1)> 2
Ready.
SPI> W
POWER SUPPLIES ON
SPI> [0x9F r:4]
CS ENABLED
WRITE: 0x9F
READ: 0x1C 0x31 0x15 0x1C
CS DISABLED
SPI>

Flashrom
Code: [Select]
53	0.00065535	flashrom.exe	IRP_MJ_WRITE	VCP0	SUCCESS	Length 1: 00 	
54 0.01508169 flashrom.exe IRP_MJ_READ VCP0 SUCCESS Length 5: 42 42 49 4F 31
55 0.00098858 flashrom.exe IRP_MJ_WRITE VCP0 SUCCESS Length 1: 01
56 0.00701392 flashrom.exe IRP_MJ_READ VCP0 SUCCESS Length 4: 53 50 49 31
57 0.00089599 flashrom.exe IRP_MJ_WRITE VCP0 SUCCESS Length 1: 4B
58 0.01500788 flashrom.exe IRP_MJ_READ VCP0 SUCCESS Length 1: 01
59 0.00091818 flashrom.exe IRP_MJ_WRITE VCP0 SUCCESS Length 1: 67
60 0.01473140 flashrom.exe IRP_MJ_READ VCP0 SUCCESS Length 1: 01
61 0.00113876 flashrom.exe IRP_MJ_WRITE VCP0 SUCCESS Length 1: 8A
62 0.01400693 flashrom.exe IRP_MJ_READ VCP0 SUCCESS Length 1: 01
63 0.00094890 flashrom.exe IRP_MJ_WRITE VCP0 SUCCESS Length 1: 03
64 0.01502921 flashrom.exe IRP_MJ_READ VCP0 SUCCESS Length 1: 01
65 0.00073514 flashrom.exe IRP_MJ_WRITE VCP0 SUCCESS Length 1: 02
66 0.01102412 flashrom.exe IRP_MJ_READ VCP0 SUCCESS Length 1: 01
67 0.00050346 flashrom.exe IRP_MJ_WRITE VCP0 SUCCESS Length 5: 13 9F 00 00 00
68 0.01300597 flashrom.exe IRP_MJ_READ VCP0 SUCCESS Length 5: 01 00 18 7F FF
69 0.00095231 flashrom.exe IRP_MJ_WRITE VCP0 SUCCESS Length 1: 03
70 0.01499337 flashrom.exe IRP_MJ_READ VCP0 SUCCESS Length 1: 01
71 0.00030976 flashrom.exe IRP_MJ_WRITE VCP0 SUCCESS Length 1: 00
72 0.00495015 flashrom.exe IRP_MJ_READ VCP0 SUCCESS Length 5: 42 42 49 4F 31
73 0.00094079 flashrom.exe IRP_MJ_WRITE VCP0 SUCCESS Length 1: 0F
74 0.00000171 flashrom.exe IRP_MJ_CLEANUP VCP0 SUCCESS
75 0.13480893 flashrom.exe IRP_MJ_CLOSE VCP0 SUCCESS

Sometimes buspirate returns 01 00 18 7F FF others 01 00 1F FF FF, on manual mode it always reads it correctly
12
Flashrom / Re: Adding Bus Pirate support to flashrom?
[quote author="ian"]
Quote
Request:

 13 9F 00 00 00                                    .Ÿ...          

Answer:

 01 00 1F FF FF                                    ...ÿÿ          

Thanks! This is a ton of help. I'll work on this today. I'm guessing this shows the elusive preceding 0x00 byte.
[/quote]

But the 0x00 is not the only problem.

On manual mode (as shown before) the chip answers to 0x9F with 0x1C 0x3F, but on that raw spi mode the buspirate after that first 0x00 byte shows 0x1F 0xFF and that is still wrong, so, maybe its mixing bits in the buffer or something.
13
Flashrom / Re: Adding Bus Pirate support to flashrom?
Got a log!

Command Line:
Code: [Select]
C:>flashrom -p buspiratespi:dev=COM5 -c EN25F16 -V
flashrom v0.9.1-r905
SPI speed is 8MHz
Raw bitbang mode version 1
Raw SPI mode version 1
Calibrating delay loop... 619M loops per second, 100 myus = 0 us. OK.
Probing for Eon EN25F16, 2048 KB: RDID[u][b] returned 0x1f 0xff 0xff[/b][/u]. probe_spi_rdid_generic: id1 0x1f, id2 0xffff
No EEPROM/flash device found.
If you know which flash chip you have, and if this version of flashrom
supports a similar flash chip, you can try to force read your chip. Run:
flashrom -f -r -c similar_supported_flash_chip filename

Note: flashrom can never write when the flash chip isn't found automatically.
Raw bitbang mode version 1
Bus Pirate shutdown completed.

Serial Comunication Log:
Code: [Select]
Port opened by process "flashrom.exe" (PID: 848)

Request:

 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00   ................
 00 00 00 00                                       ....           

Answer:

 42 42 49 4F 31                                    BBIO1          

Request:

 01                                                .              

Answer:

 53 50 49 31                                       SPI1           

Request:

 4B                                                K              

Answer:

 01                                                .              

Request:

 67                                                g              

Answer:

 01                                                .              

Request:

 8A                                                Å               

Answer:

 01                                                .              

Request:

 03                                                .              

Answer:

 01                                                .              

Request:

 02                                                .              

Answer:

 01                                                .              

Request:

 13 9F 00 00 00                                    .Ÿ...          

Answer:

 01 00 1F FF FF                                    ...ÿÿ          

Request:

 03                                                .              

Answer:

 01                                                .              

Request:

 00                                                .              

Answer:

 42 42 49 4F 31                                    BBIO1          

Request:

 0F                                                .              

Port closed
14
Flashrom / Re: Adding Bus Pirate support to flashrom?
Ok, I'll try to log the comms.
As for sending a dummy byte first, it has to be done on the PC program flashrom, and I don't think I know how to do it just yet.
Our best shot is to fix the firmware, since it works on v3, and manual SPI mode, the defect is on the firmware.
15
Flashrom / Re: Adding Bus Pirate support to flashrom?
Ok, now I'm almost shure it's the newer versions of the BusPirate firmware who are to blame!

I've found someone with a similar unsolved problem on another topic: http://dangerousprototypes.com/forum/index.php?topic=651.msg5970
Quote
Hi,

I'm currently debugging a problem with a flashrom user who has a Bus-Pirate V3 with Firmware v4.5. The problem manifests itself as an all-0x00 read from SPI for the first SPI command.

Seems that it only works on v3 firmwares.

Now, how will I downgrade the firmware? Since from v4 upwards the bootloaders are different/incompatible.