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Type: Posts; User: AlanK

1. ## Thread: Peak tracking problem.

by AlanK
Replies
15
Views
352

### Hi, That does seem to be a fairly robust way...

Hi,

That does seem to be a fairly robust way of doing it - well done!

So, if for sample n, you compare the sign of the sum of d(n-9) to d(n-5) with the sign of the sum of d(n-4) to d(n), where...
2. ## Thread: Peak tracking problem.

by AlanK
Replies
15
Views
352

### Hi, Fitting a straight line to the slope of your...

Hi,
Fitting a straight line to the slope of your curve is similar to fitting a quadratic to the data - they will give very slightly different results but the difference will be negligible.
Fitting...
3. ## Thread: Simple/cheap PCB creation on Linux

by AlanK
Replies
16
Views
412

### I use EasyEDA. It was recommended to me by a...

I use EasyEDA. It was recommended to me by a colleague with lots of experience, and I've had no problems with it.
4. ## Thread: MAX31865 and Adafruit RTD library on Teensy 4.1 problem

by AlanK
Replies
3
Views
146

### Hi Steve, I'm using those boards but with...

Hi Steve,
I'm using those boards but with hardware SPI. Are you sure that board will work with a 3.3V supply? I'm using 5V. Have you checked what the voltage is at the 3.3V output on the breakout...
5. ## Thread: a float = 223.98 prints 223.9799957

by AlanK
Replies
5
Views
386

### Here's one suggestion. This int n =...

Here's one suggestion. This

int n = 7-ceil(log10(data));
sprintf(dn, "%.*f",n, data);
will convert 7 significant figures, which are all that are accurately stored in a float, but will include...
6. ## Thread: Draw filter curves on the display

by AlanK
Replies
8
Views
422

### Hi, You'll find code to calculate biquad filter...

Hi,
You'll find code to calculate biquad filter response here:
https://forum.juce.com/t/draw-frequency-response-of-filter-from-transfer-function/20669/2
7. ## Thread: Problem using AudioInputI2Sslave and AudioOutputUSB together

by AlanK
Replies
12
Views
349

### Hi, This is just a suggestion - I haven't tried...

Hi,
This is just a suggestion - I haven't tried it. The AudioOutputUSB object doesn't cause the library to update, but adding the AudioInputI2S does so that's why that version works. Perhaps the...
8. ## Thread: Teensy 4.1 SPRAM chip availability

by AlanK
Replies
12
Views
590

### I got one of these:...

I got one of these:
https://lcsc.com/product-detail/RAM_Lyontek-Inc-LY68L6400SLIT_C261881.html
from LCSC. On paper, it looks suitable, but I haven't tested it yet with a Teensy 4.1. I hope to do...
9. ## Thread: AudioPlaySerialflashRaw and Multiple Flash Chips

by AlanK
Replies
8
Views
632

### Hi Chris, I have it working with two flash chips...

Hi Chris,
I have it working with two flash chips using SPI (using pins 6 and 10 for chip selects), implemented in the simplest brute force way. To play raw files simultaneously from both, I've...
10. ## Thread: 1Gb flash chip

by AlanK
Replies
0
Views
277

### 1Gb flash chip

Hi,
The Micron N25Q00AA 1Gb flash chip stated to work with SerialFlash appears to be obsolete. I can confirm that the newer Micron MT25QL01GBBB1EW9-0SIT also works
11. ## Thread: using parallel ports with teensy 4.0

by AlanK
Replies
12
Views
616

### Hi Ricardo, Yes. For example int x = GPIO6_DR;...

Hi Ricardo,
Yes. For example
int x = GPIO6_DR;
All the best,
Alan
12. ## Thread: using parallel ports with teensy 4.0

by AlanK
Replies
12
Views
616

### Hi, The list below has the Teensy 4.0 pins and...

Hi,

The list below has the Teensy 4.0 pins and the corresponding registers and bit numbers. The registers are 32-bit. A read from GPIO6_DR will get all 32 bits but only 12 of them correspond to...
13. ## Thread: AudioPlaySerialflashRaw and Multiple Flash Chips

by AlanK
Replies
8
Views
632

### Thanks Chris, I'm using a Teensy 4.1, so there...

Thanks Chris,
I'm using a Teensy 4.1, so there are three SPI busses available. I'll try with two flash chips on two busses and see if I can get that to work - I'll let you know if I've any success,...
14. ## Thread: AudioPlaySerialflashRaw and Multiple Flash Chips

by AlanK
Replies
8
Views
632

### Hi Chris, I'm trying to do the same thing using...

Hi Chris,
I'm trying to do the same thing using a Teensy 4.1. I have two flash chips on the SPI bus, have copied raw files to both, can play from both separately, but my attempts so far at playing...
15. ## Thread: Problem with numbering of objects in Audio System Design Tool

by AlanK
Replies
5
Views
331

### Sorry for posting to the wrong place. It happens...

Sorry for posting to the wrong place. It happens in Chrome (Version 84.0.4147.105 (Official Build) (64-bit)) and in Edge (Version 84.0.522.52 (Official build) (64-bit)). The problem is not with...
16. ## Thread: Problem with numbering of objects in Audio System Design Tool

by AlanK
Replies
5
Views
331

### Problem with numbering of objects in Audio System Design Tool

Hi,
There's a minor bug in the design tool. If, for example, you drag on one Mixer, and then copy and paste that Mixer, the two are named Mixer1 and Mixer2. If you then drag on another mixer,...
17. ## Thread: Problem changing AUDIO_BLOCK_SAMPLES

by AlanK
Replies
5
Views
403

### Hi Paul, Thanks for clarifying that, All...

Hi Paul,

Thanks for clarifying that,

All the best,

Alan
18. ## Thread: Problem changing AUDIO_BLOCK_SAMPLES

by AlanK
Replies
5
Views
403

### Hi Paul, I didn't - it was working with...

Hi Paul,
I didn't - it was working with AUDIO_BLOCK_SAMPLES set to 32 on a 4.0 using an audio shield for output. I've been working on other aspects of my software, and have moved to a 4.1 -...
19. ## Thread: Problem changing AUDIO_BLOCK_SAMPLES

by AlanK
Replies
5
Views
403

### Hi, Could the fixing of USB Audio for Teensy 4.x...

Hi,
Could the fixing of USB Audio for Teensy 4.x have introduced a problem when
AUDIO_BLOCK_SAMPLES is changed?
20. ## Thread: Problem changing AUDIO_BLOCK_SAMPLES

by AlanK
Replies
5
Views
403

### Problem changing AUDIO_BLOCK_SAMPLES

Hi,

I had reduced AUDIO_BLOCK_SAMPLES to 32 previously to reduce latency in an audio project and it worked perfectly (and significantly reduced the latency). That was using a Teensy 4.0 with audio...
21. ## Thread: Measuring distance... with sound?

by AlanK
Replies
23
Views
1,023

### I agree - there are lots of potential problems....

I agree - there are lots of potential problems. The speed of sound in air is highly temperature dependent, so you'll have difficulty getting accuracy of +/-1mm over a 20cm range for that reason alone...
22. ## Thread: Measuring distance... with sound?

by AlanK
Replies
23
Views
1,023

### Hi, What about having a single tone produced at...

Hi,
What about having a single tone produced at A, a second tone at twice that frequency produced at joint 2 (or some other fixed distance from B), with both synchronised, and a microphone at B? Use...

by AlanK
Replies
3
Views
300

### Hi, I don't have the answers to some of your...

Hi,
I don't have the answers to some of your questions, but, with a Teensy 4.0, I can reliably send 18 byte chunks 50,000 times per second over Serial USB. My data is coming from an external ADC...
24. ## Thread: AudioDelayEffect() Maximum Delay Time on Teensy 4.0

by AlanK
Replies
2
Views
184

### Hi, Look here ...

Hi,
Look here and here for the answer and how you might extend it if you want
25. ## Thread: Renaming a board in Windows

by AlanK
Replies
3
Views
183

### Sorry, You didn't say you were using an LC - you...

Sorry,
You didn't say you were using an LC - you can't use name.c with it. Try looking at this thread - it seems to give a solution. I've no experience with the LC so I can't do much more than point...

by AlanK
Replies
3
Views
183

27. ## Thread: Teensy 4.0 USB transfers per second

by AlanK
Replies
6
Views
315

### Hi, Try adding Serial.setTimeout(1); after...

Hi,
Serial.setTimeout(1);
after Serial.begin.
28. ## Thread: Teensy 4.1 Beta Test

by AlanK
Replies
797
Views
48,877

### Could it be left flexible enough so that two...

Could it be left flexible enough so that two flash (or two PSRAM) chips could be recognised?
29. ## Thread: Teensy 4.0 USB transfers per second

by AlanK
Replies
6
Views
315

### Hi, At what rate do you want to transfer data,...

Hi,
At what rate do you want to transfer data, and how are you receiving it on your PC? I have an application
, for example, that transmits serial data from a Teensy 4.0 over USB at roughly 200...
30. ## Thread: On AudioPlaySdWav to play drum machine samples

by AlanK
Replies
2
Views
169

### Hi, There's a similar thread here...

Hi,
There's a similar thread here that may help you. What I would advise you to do is first try things the easiest way using the audio library to play samples directly from the SD card. If you find...
31. ## Thread: Teensy 4.1 Beta Test

by AlanK
Replies
797
Views
48,877

### Hi, I haven't seen them, but I presume that,...

Hi,
I haven't seen them, but I presume that, because of the duplication, most of the pogo pins could be 0.254 apart. Only two would have to go to pads that are adjacent. I don't know how long the...
32. ## Thread: Problem operand with float

by AlanK
Replies
5
Views
240

### Hi, I would expect you to get the same result as...

Hi,
I would expect you to get the same result as before -
45.0001182 or
45.0001183. You won't do any better than that if you convert the result to a float.
If you need more accuracy that that,...
33. ## Thread: Problem operand with float

by AlanK
Replies
5
Views
240

### Hi, Round-off errors in floats limit the...

Hi,
Round-off errors in floats limit the accuracy to roughly seven significant figures - not seven decimal places
34. ## Thread: Teensy 4.1 Beta Test

by AlanK
Replies
797
Views
48,877

### Yes, the upper 16 bits of GPIO6_DR are mapped to...

Yes, the upper 16 bits of GPIO6_DR are mapped to pins 19 (bit 16), 18, 14, 15, 40, 41, 17, 16, 22, 23, 20, 21, 38, 39, 26 and 27 (bit 31) on the 4.1.
35. ## Thread: How to connect Teensy 4.0, HC-05 and MPU9250

by AlanK
Replies
2
Views
322

### Hi, I've used a HC-05 connected to a Teensy 3.6...

Hi,
I've used a HC-05 connected to a Teensy 3.6 and powered directly from VIN (5V). The logic pins are 3.3 V. Some HC-05 modules have a button for forcing them into AT mode - that will make life...
36. ## Thread: Teensy 4.1 Beta Test

by AlanK
Replies
797
Views
48,877

### Thanks for clarifying that. I'm thinking about...

Thanks for clarifying that. I'm thinking about accessing those pads using pogo pins - I have two 1Gb flash chips but they are SOIC-16.
All the best,
Alan
37. ## Thread: Write from SD Card to RAM

by AlanK
Replies
7
Views
405

### Hi, A SOIC-8 chip is quite easy to solder - but...

Hi,
A SOIC-8 chip is quite easy to solder - but I would recommend getting a magnifier if you don't have one. I can do it despite shaky hands and bad eyesight!

When I said layered sounds, I meant...
38. ## Thread: Write from SD Card to RAM

by AlanK
Replies
7
Views
405

Answering your original question, I would advise you to first convert the sound files to RAW format (you could use Audacity, for example). RAW files don't have headers so it will be easier for you to...
39. ## Thread: Teensy 4.1 Beta Test

by AlanK
Replies
797
Views
48,877

### Hi, The three RAM/flash chips Paul has...

Hi,

The three RAM/flash chips Paul has tested all have 1.27 mm pitch as far as I can tell. Is that the pitch for both sets of pads?
40. ## Thread: Write from SD Card to RAM

by AlanK
Replies
7
Views
405

### Hi, If you use a flash memory chip soldered onto...

Hi,
If you use a flash memory chip soldered onto the Audio board (i.e. using SPI) then, from experience, you should not have a problem playing enough simultaneous samples for a drum machine using...
41. ## Thread: Can 3.3 V be safely applied to a Teensy 4 I/O pin while the Teensy 4 power is off?

by AlanK
Replies
7
Views
481

### Hi PDOS, Sorry for giving wrong information....

Hi PDOS,

Sorry for giving wrong information. I'm not in a position to check my original setup at the moment - it's in my office and I can't go there,

Good luck
42. ## Thread: Playing two (or more) RAW files

by AlanK
Replies
5
Views
2,146

### Hi NewtonBIV, Try running the editor as...

Hi NewtonBIV,
Try running the editor as Administrator if you're using Windows - then you should be able to save the changes.
43. ## Thread: Can 3.3 V be safely applied to a Teensy 4 I/O pin while the Teensy 4 power is off?

by AlanK
Replies
7
Views
481

### Hi, I've used a Teensy 4.0 connected to an ADC...

Hi,
I've used a Teensy 4.0 connected to an ADC evaluation board that was powered separately, and there was never any problem. There were output pins that were normally HIGH from the eval board, and...
44. ## Thread: Analog and Digital through one socket - AGND OK?

by AlanK
Replies
3
Views
261

### Hi, Could you use an ADC input for both, and...

Hi,
Could you use an ADC input for both, and just use a threshold in your code for the digital input?
45. ## Thread: The state of SPI Flash support

by AlanK
Replies
10
Views
607

### Hi, You may find that the only SPI 2Gb NOR...

Hi,

You may find that the only SPI 2Gb NOR flash chips are BGA - so you may need to go the insane route!
46. ## Thread: The state of SPI Flash support

by AlanK
Replies
10
Views
607

### Hi, Be careful - the size of flash chips is...

Hi,

Be careful - the size of flash chips is normally given in Mbits. So, if you want a single chip capable of storing 1GB, look for one that's at least 8Gb capacity. That will limit you to NAND...
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