MicroSD drawing too much current?

Projects General Guidance
1

Hi there,

I am using the microSD module by adafruit and am encountering some issues.

First of all, I noticed that the module can draw up to 100 mA of current at a point. In my application this module is tied to the same 3V3 rail as other sensors, a display and a Bluetooth module.

When using this module, it looks like my data coming from the Bluetooth HC-06 module becomes corrupted and I am unable to interpret any data.

Both modules work independently. Is there anyway to fix this?

A subpar picture of the hardware: https://drive.google.com/file/d/1bgggXI ... sp=sharing

Daniel

Esperto_FW.ino (18.4 KB)

2

Is there anyway to fix this?

What is the problem? The card NEEDS up to 100mA (or sometimes more) of current. You MUST provide a power supply capable of supply that much current. The onboard 3.3V regulator is NOT.

3

ddesousa:
First of all, I noticed that the module can draw up to 100 mA of current at a point.

In my application this module is tied to the same 3V3 rail as other sensors, a display and a Bluetooth module.

A subpar picture of the hardware

The module runs on fumes (74HC4050), but the CARD could use up to 150mA.

Why don't you use the module's onboard 3.3volt voltage regulator.

Which Arduino do you use, and where is your code.
Link does not work.
Leo..

4

A copy of my code: https://drive.google.com/file/d/1z2jQqirSWXDxySJKcdbpqYY_Mt41-2t7/view?usp=sharing

Photo of my hardware: https://drive.google.com/file/d/1bgggXIS9Jj7m-M9eRnkdNELz6hzqKNJ-/view?usp=sharing

I am using a:
SAM D21 mini breakout (sparkfun)
0.96 " OLED Display (adafruit)
MAX30102 Heart Rate Sensor (Maxim Integrated)
HC-06 Bluetooth
MPU6050 Acceleromter (DFRobot)

I brought up this problem as I have noticed that my Bluetooth module cuts off some information when I recieve it and this has been happening ever since I implemented the SD Reader.

Something like a time will go from 11:20;23 PM to 1:20:23 PM.

Thanks

5

I think I see badly soldered pins on the micro board, and some pins not soldered at all.

Don't know these micro boards, but the schematic diagram shows that "V-in" (pin1) is USB supply through a backflow protection p-channel mosfet. This (naming) is different from regular Arduinos.

The HC-06 modules I know must be powered from 5volt, because they have their own 3.3volt regulator.
I think I see that you power the HC-06 from the V-in pin.
But why power the SD from the 3.3volt pin of the micro (with a tiny onboard 3.3volt regulator), when the SD card has it's own regulator. Just power the SD card (5volt pin) also to the V-in pin of the micro.
Don't know which MPU6050 you have (post links).
Leo..

6

Hi Wawa,

Thanks for your questions.

I think I see badly soldered pins on the micro board, and some pins not soldered at all.

I can confirm all the pins are soldered properly. The devices work just not together.

Don't know these micro boards, but the schematic diagram shows that "V-in" (pin1) is USB supply through a backflow protection p-channel mosfet. This (naming) is different from regular Arduinos.

The HC-06 module is being powered by VIN as it disrupts the rest of the module when connected to 3v3. The modules data sheet says it is rated for supply anywhere between 3.6 and 6 V

But why power the SD from the 3.3volt pin of the micro (with a tiny onboard 3.3volt regulator), when the SD card has it's own regulator. Just power the SD card (5volt pin) also to the V-in pin of the micro.

This is a 3V3 based application. In the end, I will be using a 3.7 V battery to power the mcu and regulate the 3v3 voltage using the on board regulator.

Don't know which MPU6050 you have (post links).

SAM D21 mini breakout https://www.sparkfun.com/products/13664
0.96 " OLED Display
MAX30102 Heart Rate Sensor Mixed-signal and digital signal processing ICs | Analog Devices
HC-06 Bluetooth
MPU6050 Acceleromter 6_DOF_Sensor-MPU6050__SKU_SEN0142_-DFRobot

Note: When I remove the heart rate algorithm, everything seems to work fine. Could the algorithm be taking up too much processing time?

Dan

7

Hi,

Please read the first post in any forum entitled how to use this forum.
http://forum.arduino.cc/index.php/topic,148850.0.html then look down to item #7 about how to post your code.
It will be formatted in a scrolling window that makes it easier to read.

Some platforms and members, do not like going off forum to get code or images.

Thanks.. Tom... :slight_smile:

8

ddesousa:
The HC-06 module is being powered by VIN as it disrupts the rest of the module when connected to 3v3. The modules data sheet says it is rated for supply anywhere between 3.6 and 6 V

This is a 3V3 based application. In the end, I will be using a 3.7 V battery to power the mcu and regulate the 3v3 voltage using the on board regulator.

I see two problems here.
First: the voltage of your battery will most of the time be lower than 3.7V so you're really at or under the specified limit for the HC06 module. You better find a Bluetooth module that's designed for 3.3V.

Second: I doubt the regulator on your board has that low a minimum drop-out. I think there are some regulators that indeed do 0.4V but most are above that, and anyway the moment your voltage drops below 3.7V even that 0.4V drop-out gets you below 3.3V.

9

Hi,
To quote the adafruit site;

  • Onboard 5v->3v regulator provides 150mA for power-hungry cards

Tom... :slight_smile:

10

First: the voltage of your battery will most of the time be lower than 3.7V so you're really at or under the specified limit for the HC06 module. You better find a Bluetooth module that's designed for 3.3V.

Okay I agree but I am currently powering the Bluetooth module with USB power anyways which is currently about 4.3 V

Some platforms and members, do not like going off forum to get code or images.

Sorry Tom but my code was too long and I wanted to provide the people in the forum with the full code.

To quote the adafruit site;

Good point. I have noticed that the SD might not be the problem. When I do not use my new heart rate module (MAXREFDES117), everything seems to work and the time and date display properly. Now , theres a complex peak detection algorithm going on in the background. Could this be disrupting the UART interface between the mcu and BT
Library: GitHub - sparkfun/SparkFun_MAX3010x_Sensor_Library: An Arduino Library for the MAX3015 particle sensor and MAX30102 Pulse Ox sensor

11

Hi,
If your code won't post to tags, attach it to the post.

How are you powering your project at the moment? Off the PC USB?

If so then what ever you have connected to Vin on the nano will not be receiving proper regulated supply.

HC-06 should be connected to 5V, as you have said it will work on 5V.

Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?

Tom... :slight_smile:

12

H Tom,

Thanks for the reply. I have attached the code to OPa.

I am powering off of USB but I have tried off a constant power supply and I obtain the same results.

Again, I do not think this is a hardware issue as both systems work independently.

I believe the HR algorithm I currently have is taking too much processing or something related to my code. Please take a look.

Thanks,

DD

13

Hi,

constant power supply and I obtain the same results.

How is the constant power supply connected, via USB or Vin and gnd?

Tom... :slight_smile:

14

Hi Tom,

I used a power supply found in my lab, powering the entire module at 5 V.

DD

15

Hi,
Through the 5V pin or through the Vin?
It should be 5V pin..

Thanks.. Tom.. :slight_smile:

16

Hi Tom.

It is being powered through the 5V pin. I have investigated further and I believe the problem actually has to do with the heart rate sensor taking too much processing.

Can we look into that?

DD