My bluetooth chip (SOC) has tx power of -6 to +8dbm and receive sensitivity of -93dbm. But my chipset manufacturer is saying max range possible is 40-50 meters only. Why is this the case? I thought BLE devices were capable of up to 100 meters. What else can I improve in the circuit to increase the range? Appreciate your help.
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i need to connect my phone to the esp32 with BLE(Bluetooth Low Energy). But only when you are close to just 1 meters. So, how can i reduce the meters? And also if you go far away from 1 meter, it has to disconnect. I would be happy, if you answer...
Unfortunately this would be very challenging to implement because you have to rely on the RSSI to approximate the distance which is not always very reliable. Have a look at these links below for more information:-
Things you should know about Bluetooth range
Using BLE for indoor positioning
Fundamentals of beacon ranging
Connect if the RSSI more than 40 and keep updating the RSSI for 2 seconds, get the average if it's more than -30 then you're too close to the device.
I am experimenting two low energy bluetooth 4. I am getting uuid, tx power level and rss values on the android app that I downloaded.
I noticed that one of these two is sending 0 for tx power level, but the other one is sending 4 for tx power level and see different RSSI values on the android app even though I put them in the same spot. It means that the distance is same between my android phone and these two bluetooth devices. If the difference is +/- 5, I understand, but the difference is +/- 15. Is is because of the tx power level?
And oo I need to take tx power level into consideration to calculate the proximity between the BLE 4 and my android app?
You cannot directly relate RSSI and absolute distance between BLE central and peripheral. Of course RSSI is affected by, but not only, distance. However there are other significant factors such as interference, transmittion medium, etc. If your two BLE peripherals are two different models, the values may even vary more.
RSSI fluctuating for around +-15 is very normal for BLE connections, and nearly impossible to eliminate in practical cases. So basically you cannot only rely on RSSI for calculating distance if you want the error to be less than several meters.
I've got an Arduino with an ATmega328 processor. It can be operated at 3.3V which nets a clock signal frequency of about 12 MHz respectively 16 Mhz at 5V.
I connected an IMU to the Arduino which runs an AHRS algorithm turning accelerometer, gyroscope and magnetometer data into orientation data.
What does the higher frequency of 16 MHz actually mean in this context?
Will the AHRS be calculated faster so I get a lower latency? Can I poll the sensors more often? I want a deeper understanding of what I'm doing here.
Higher frequency means more clock cycles per second which means more operations are done during the same duration of time. This means AHRS runs faster and you will achieve a lower latency and if you are repeatedly reading values from the IMU, you will be able to poll more often.
I understand that Bluetooth Low energy(BLE) client scan for BLE peripherals. I want to know, how far,in meters, a BLE client can scan/discover a BLE peripheral.
An iPhone 5 will detect a RadBeacon USB (BLE Beacon) set at maximum transmit power about 40 meters away. At greater distances of up to 50 meters, it might be intermittently detected, but detections are not reliable. Outdoors with clear line of sight, it can sometimes be detected at even greater distances of up to 100 meters, but again this is not reliable.
This is typical, but just an example. The specifics depend on the transmitting device, the receiving device, any physical obstructions, and how much radio noise is in the area.
I am currently using analog pin 3 on my Arduino Uno to send out voltage from 0 to 5V.
I am using that voltage to control the motor and currently I am using the function:
analogWrite(pin, PWM_PULSE);
I am using 255 pwm for 5V and 127 for 2.5V.
The problem is that PWM is sending full cycle at 255pwm(5V), but on 127V the cycle is at 50% which causes my motor to twitch a little bit.
How can I solve this? I am searching for a way to send full PWM cycle even at lower volts. Is it possible?
First I believe you mean D3 not A3, since PWM does not exist on A3.
Assuming you are driving a DC motor, and not something like a servo or stepper
You have two problems.
1st. you may need a smoothing capacitor. Where your formula would be F=L*C Noting that analogWrite uses a F=490Hz. The concept is simple, in short the cap average out the high and lows of the PWM, based on the duty cycle. And the capacitance needed is based on the frequency and impedance. This will provide the analog voltage.
2nd. And bigger problem is the output of the Arduino can not supply sufficient current to drive the motor correctly. It will max out at about 20ma, and the motor likely needs more. So at low speeds the pulses which were week, stall out during their low periods.
You should have your PWM output drive a transistor, which in turn will ON-OFF the motor directly from the power supply. Now your motor may have enough inertia as not to need the cap.
see adafruit-arduino-lesson-13-dc-motors/breadboard-layout
and here for a discussion about the smoothing cap