Open Source Hardware

[Holden202T]

I thought id see what all the fuss was about

looks like the its a nice compact design .... but at the expense of a 4 layer pcb.

i sorta wonder why some of the components like the resistors and stuff are so small when there is plenty of space on the board for them to be larger ? purely thinking from a DIY point of view ... i also wonder how big it would be if it was made into a 2 layer board .... using the website where i normally get PCB's made, its $4.90 for 10 PCBs in 2 layer, its $50 for 4 layer boards .... and as long as they are under 100 x 100mm in size ..... this one is 45 x 75mm

[j_ds_au]

4. Would 863-NCP730ASN500T1G be a good replacement for 621-AP2204K-5.0TRG1 ??
5. Would 863-NCP730ASN330T1G be a good replacement for 621-AP2204K-3.3TRG1 ??
6. Would 863-NCP730ASNADJT1G be a good replacement for 621-AP2204K-ADJTRG1 ??

I don't know what things like Dropout Voltage are, so I'm purely guessing on the Linear Voltage Regulators ...

The NCP730 LDO's seem a reasonable alternative to the AP2204K LDO's. Possible issues are that the ADJ version will have a 3.33% lower output voltage (unless one or both the feedback resistors are tweaked slightly), and you need to check that the design meets the stability requirement "requires the output capacitor connected as close as possible to the output and ground pins. The LDO is designed to remain stable with output capacitor’s effective capacitance in range from 1 μF to 100 μF and ESR from 1 mΩ to 200 mΩ. The ceramic X7R or X5R type is recommended due to its low capacitance variations over the specified temperature range and low ESR."

Dropout is what happens when you reduce the input voltage of a regulator too far, so that it's unable to sustain its correct output voltage. Dropout Voltage is the voltage difference between the input and output, below which dropout will/may occur. Low Dropout (LDO) is a regulator type that features a low Dropout Voltage, as compared to traditional regulators such as the μA7800 series. However, LDO's tend to have specific requirements to maintain stability, and may otherwise be prone to oscillation.

Joe.

[antus]

i sorta wonder why some of the components like the resistors and stuff are so small when there is plenty of space on the board for them to be larger ? purely thinking from a DIY point of view ... i also wonder how big it would be if it was made into a 2 layer board .... using the website where i normally get PCB's made, its $4.90 for 10 PCBs in 2 layer, its $50 for 4 layer boards .... and as long as they are under 100 x 100mm in size ..... this one is 45 x 75mm

I guess it was going to be a commercial product, but then competition got cheaper and this looked less viable. I dont think the original intention was for it to be DIY, but good on beyerch for putting it out there for others when he stopped working on it.

[Gampy]

jlcpcb.com is quoting US$8.00 for 5 boards with free assembly, but they only populate the components they have in stock, they do not have the MCU, they do not accept customer components and the MCU is the hardest component to hand job being such a narrow pitch.
BTW, 2 layer is US$2.00 for 5 boards ...

Thank you Joe!
Would I be better off trying to find the 7800 series, a quick look shows adjustable, no fixed ??
Fortunately I got a scope a year ago that's been collecting dust, all I have to is learn how to use it!

Where is this competition ??

[Gampy]

Whoo Freaking Hooo!

Don't be too easily fooled, I faked the missing TimeoutCallback (raised issue on github), commented out a single call to isotp_send_ext(...) that is missing (raised issue on github) and fixed an attempt to modify a const ...
Of course that was after dealing with the missing libraries bitfield-c and isotp-c, without crap like cygwin!

I really don't figure that too bad for unfinished work, I have built (or tried) supposed production ready work that was far worse.

[edit]
Damn this Microchip branded Visual Studio is a pig ... VS2019 runs awesome on this W10 box, Microchip Studio bogs down hardcore (gets slower and slower) then crashes!

[j_ds_au]

Thank you Joe!
Would I be better off trying to find the 7800 series, a quick look shows adjustable, no fixed ??
Fortunately I got a scope a year ago that's been collecting dust, all I have to is learn how to use it!

No, the μA7800 series regulators would not be good substitutes. They are traditional non-LDO types, which I mentioned just to contrast against the LDO types that you need. This was just to help explain what Dropout and Low Dropout were all about.

Joe.

[Gampy]

No, the μA7800 series regulators would not be good substitutes. They are traditional non-LDO types, which I mentioned just to contrast against the LDO types that you need. This was just to help explain what Dropout and Low Dropout were all about.

Joe.

Thank ya sir!

[Gampy]

While perusing the firmware code I came across an interesting comment ... kcan.c#L364

[Holden202T]

brick wall ?

[geep]

was the firmware never completed on this project just curious